REGAINING CONTROL – DRUM-BUFFER-ROPE IN MADE-TO-

ORDER APPAREL MANUFACTURING

ARUSH DIXIT & VASHISTHA IYER \

Department of Fashion Technology National Institute of Fashion Technology, Gandhinagar

May, 2010

REGAINING CONTROL – DRUM-BUFFER-ROPE IN MADE-TO-

ORDER APPAREL MANUFACTURING

A dissertation submitted in partial Fulfillment of the requirement for the award of Degree

in

Bachelor of Fashion Technology (Apparel Production)

Submitted By

ARUSH DIXIT & VASHISTHA IYER

Under the Guidance of

MR. MANOJ TIWARI

Department of Fashion Technology National Institute of Fashion Technology, Gandhinagar

May, 2010

Index

Abstract ............................................................................................................................................ i

Certificate ........................................................................................................................................ ii

Acknowledgements ........................................................................................................................ iii

List of Tables ................................................................................................................................. iv

List of Figures ................................................................................................................................. v

01. Introduction ............................................................................................................................... 1

1.1. Objectives ............................................................................................................................. 4

02. Review of Literature ................................................................................................................. 5

2.1 Production Concepts & Applications .................................................................................... 6

2.2. Theory of Constraints ......................................................................................................... 18

2.3. V/A/T Analysis & Synchronous Manufacturing ................................................................ 20

2.4. Drum-Buffer-Rope Scheduling .......................................................................................... 23

2.2 List of References................................................................................................................ 28

03. Methodology ........................................................................................................................... 29

3.1. Scope of Research .............................................................................................................. 30

3.2. Assumptions ....................................................................................................................... 30

3.3. Constraints .......................................................................................................................... 30

3.3.1. Identifying the Constraint ............................................................................................ 31

3.3.2. V/A/T and 5 Why Analysis ......................................................................................... 31

3.3.3. Design of Constraint .................................................................................................... 32

3.4. Applying Drum-Buffer-Rope ............................................................................................. 33

3.4.1. Establishing Time Buffers ........................................................................................... 34

3.4.2. Creating a Drum Schedule ........................................................................................... 34

3.4.3. Buffer Management ..................................................................................................... 35

3.4.4. Comparison of Existing & Proposed Systems ............................................................. 35

04. Constraints .............................................................................................................................. 37

4.1. Identifying the System’s Constraint ................................................................................... 40

4.2. Designing the System’s Constraint .................................................................................... 45

4.3. Exploiting the System’s Constraint .................................................................................... 46

05. Drum-Buffer-Rope .................................................................................................................. 50

5.1. The Drum ........................................................................................................................... 51

5.2. The Buffer .......................................................................................................................... 52

5.3. The Rope ............................................................................................................................ 55

5.4. Drum-Buffer-Rope Schedule ............................................................................................. 56

5.5. Buffer Management............................................................................................................ 61

5.5.1 Local Control – Buffer status ....................................................................................... 63

5.5.2. Global Feedback - Buffer Hole ................................................................................... 64

5.5.3. Global Feedback –Reason code analysis ..................................................................... 65

5.5.4 Local Measurements ..................................................................................................... 66

06. Results ..................................................................................................................................... 69

6.1. Planned v/s Actual .............................................................................................................. 70

6.2. The Drum-Buffer-Rope Schedule ...................................................................................... 72

6.3. New v/s Old ........................................................................................................................ 74

07. Limitations and Scope of Further Study ................................................................................. 75

7.1. Limitations ......................................................................................................................... 76

7.2. Scope for Further Study ..................................................................................................... 77

08. Conclusion .............................................................................................................................. 79

8.1. Recommendations .............................................................................................................. 82

09. Bibliography ........................................................................................................................... 84

Mabin J. Victoria & Steven J. Balderstone “The world of the theory of constraints: a review of the international literature” CRC Press (2000) ............................................................................. 85

Appendices .................................................................................................................................... 87

Appendix A ................................................................................................................................ vi

Appendix B ............................................................................................................................... vii

Appendix C.1 ........................................................................................................................... viii

Appendix C.2 ............................................................................................................................. ix

Appendix C.3 .............................................................................................................................. x

Appendix C.4 ............................................................................................................................. xi

Appendix D ............................................................................................................................... xii

Appendix E ............................................................................................................................... xiii

Appendix F ............................................................................................................................... xiv

Appendix G.1 ............................................................................................................................ xv

Appendix G.2 ........................................................................................................................... xvi

Appendix G.3 .......................................................................................................................... xvii

Appendix G.4 ......................................................................................................................... xviii

Appendix G.5 ........................................................................................................................... xix

Appendix G.6 ............................................................................................................................ xx

Appendix G.7 ........................................................................................................................... xxi

Appendix G.8 .......................................................................................................................... xxii

Appendix G.9 ......................................................................................................................... xxiii

Appendix H ............................................................................................................................ xxiv

Appendix I ............................................................................................................................... xxv

Appendix J.1........................................................................................................................... xxvi

Appendix J.2.......................................................................................................................... xxvii

Appendix K .......................................................................................................................... xxviii

Annexures .................................................................................................................................. xxix

Annexure 1 ................................................................................................................................ xxx

i

Abstract

Apparel companies are continuously exploring different philosophies to improve their

operations. Amongst others, Theory of Constraints provides the simplest solution for production

in the form of Drum-Buffer-Rope scheduling, an application which does not require large sets of

data, extensive worker training or lower level buy-in. This paper illustrates how a drum-buffer-

rope application can be designed and implemented in a high-mix/low-volume made-to-order

apparel manufacturing environment. It addresses the various issues that apparel manufacturers

could face when beginning to implement a Theory of Constraints application. The

implementation was carried out in an apparel export house in Jaipur, Rajasthan and showed

that drum-buffer-rope can be successfully applied to even small and medium sized companies

enabling them to achieve dramatic improvements in due-date performance and substantial

reduction in lead times and inventories. Of the various benefits that Drum-Buffer-Rope can

provide, the most immediate one is a production schedule which actually works despite the

common culprits such as unreliable vendors, absenteeism, machine breakdowns, absence of

accurate data, unreliable processes and quality problems. Such a high performing schedule

leads to a high performing and stable system. This stability must be used as the cornerstone to

kick start a process of ongoing improvement in the pursuit of operational excellence.

ii

Certificate

“This is to certify that this Project Report titled “Regaining Control – Drum-Buffer-Rope in

Made-to-Order Apparel Manufacturing” is based on our, Arush Dixit’s & Vashishtha Iyer’s

original research work, conducted under the guidance of Mr. Manoj Tiwari towards partial

fulfillment of the requirement for award of the Bachelor’s Degree in Fashion Technology

(Apparel Production), of the National Institute of Fashion Technology, Gandhinagar.

No part of this work has been copied from any other source. Material, wherever borrowed

has been duly acknowledged.

Arush Dixit

Vashistha Iyer

iii

Acknowledgements

We are extremely grateful to National Institute of Fashion Technology for making this

exercise in effect with the curriculum. The project would not have been completed without the

timely efforts and involvement of our mentor Mr. Manoj Tiwari (Asst. Professor, DFT) and Ms.

Amisha Mehta (CC-DFT). Their guidance is an indispensable part of this research work.

We express our heartfelt gratitude to Mr.Rajiv Dewan (CEO) and Mr. Rakesh Dewan

(Director), Ma’Am Arts, Jaipur for their candid didactics on the apparel export business and for

allowing us to pursue our graduation project with their company.

Mr. Varun Mishra (General Manager - Production) deserves a special mention for providing

the required support during the implementation phase of the project and for those endless

debates about the project and related concepts. We are also thankful to the staff of Ma’Am Arts

for their support and coordination.

Last but not the least we thank our parents and friends for being a constant source of support

and inspiration.

iv

List of Tables

Table 4.1 - Style Produced between 8th March, 2010 and 7th April, 2010 .................................... 42

Table 4.2 - Types of Packing ........................................................................................................ 48

Table 4.3 - Illustration of production within the drum ................................................................ 49

Table 5.1 A - Lead time from Material Release to Sewing for Dyed Products ............................ 53

Table 5.1 B - Lead time from Material Release to Sewing for Printed Products ......................... 53

Table 5.2 - Production Buffer Size ............................................................................................... 54

Table 5.3 A - Details of orders executed on the Drum ................................................................. 56

Table 5.3 B - Due dates of orders executed on the Drum ............................................................. 56

Table 5.4 - Estimating Work Content ........................................................................................... 57

Table 5.5 - Detail plan for Sheet No. 1732 A and 1732 B fed to Drum I consecutively .............. 59

Table 5.6 - Drum Schedule ........................................................................................................... 60

Table 5.7 - Material Release Schedule ......................................................................................... 61

Table 5.8 - Reason Code Analysis ................................................................................................ 66

Table 5.9 - Severity ....................................................................................................................... 67

Table 5.10 - Daily Severity Chart ................................................................................................. 68

Table 6.1 - Planned v/s Actual at Drum 1 on 15th April ............................................................... 70

Table 6.2 - Planned vs Actual comparison for packed output at Drum 1 ..................................... 71

Table 6.3 - Planned vs Actual comparison for packed output at Drum 2 ..................................... 72

Table 6.4 - Progress of Order scheduled by Drum-Buffer-Rope (Sundays are excluded) ........... 73

Table 6.5 - Performance Comparison ............................................................................................ 74

v

List of Figures

Figure 2.1 - Relationship between management time required and the time buffer size.............. 17

Figure 4.1 - Flowchart of Processes at MA’AM Arts, Jaipur ....................................................... 41

Figure 4.2 - Shifting Bottlenecks .................................................................................................. 43

Figure 5.1 - Drum and Buffer ....................................................................................................... 54

Figure 5.2 - Effects of Choking Material Release ....................................................................... 55

Figure 5.3 - Determining Drum Start and Material Release ......................................................... 58

Figure 5.4 - Zoning of Buffers ...................................................................................................... 62

Figure 5.5A - Buffer holes in production buffer for dyed products .............................................. 64

Figure 5.5B - Buffer holes in production buffer for printed products .......................................... 65

Figure 5.6 - Buffer Exhaustion ..................................................................................................... 66

1

01. Introduction

2

“A truly prosperous time is when the largest numbers of people are getting all they can

legitimately eat and wear, and are in every sense of the word comfortable. It is the degree of the

comfort of the people at large--not the size of the manufacturer's bank balance--that evidences

prosperity. The function of the manufacturer is to contribute to this comfort. He is an instrument

of society and he can serve society only as he manages his enterprises so as to turn over to the

public an increasingly better product at an ever-decreasing price, and at the same time to pay to

all those who have a hand in his business an ever-increasing wage, based upon the work they do.

In this way and in this way alone can a manufacturer or any one in business justify his

existence.” – Henry Ford, My Life and Work

The business of fashion in the 21st century has evolved into a complex web with the advent

of globalization transcending it beyond physical barriers between markets and manufacturers.

Increased fashion cycles have led to buyers demanding shorter lead times and exceptional due

date performance from their suppliers. While certain mass producers of apparel in India operate

world class manufacturing plants with some manufacturers even successfully running Lean and

Six Sigma philosophies, the majority of apparel manufacturers remain small to medium scale

industries with not enough management talent to execute advanced production systems. Plagued

with seasonal demand, high labor turnover and arcane systems, it seems they thrive only on low

labor costs. With even labor costs going up and the increasing availability of higher paying

alternative low skill jobs, these manufacturers must find a way to manage their operations

without heaps of inventory, uncontrollable overtime, quality problems and low due date

performance.

Solutions to these problems have been available since many decades. Taiichi Ohno presented

his Toyota Production Systems based on Just-in-Time concepts in as early as 1988. This has

3

evolved into a management philosophy called Lean Manufacturing and is being actively pursued

by competent apparel manufacturers today. Lean represents a utopian system where no wastes

should exist. From an operational point of view, it’s the ultimate objective. But consider the

plight of small and medium scale made-to-order apparel manufacturers. A lean implementation

requires stability in the system, buy-in at the floor level and a culture of continuous

improvement. Trying to implement Lean concepts in such volatile environments where each and

every order is hot, red-hot or drop-everything-else-and-make-this-urgently hot is certainly not a

pragmatic solution. What is required is a system which can provide this necessary condition of

stability – An operating mechanism which can shorten lead time, reduce inventory and deliver

exceptional due-date performance. In fact, such a mechanism does exist. It is the Theory of

Constraints Drum-Buffer-Rope Scheduling system. This paper explores the applicability of this

system a high-mix/low-volume made-to-order apparel manufacturing environment.

Theory of Constraints, introduced by Dr. Eliyhu M. Goldratt in his book “The Goal” in 1984,

is a management philosophy which advocates a systemic view of the business. It considers the

system as a chain whose strength is governed by its weakest link, the constraint. It implores the

elimination of decision making based on local efficiencies and encourages improving the global

optimum by exploiting the constraint. Drum-Buffer-Rope is the logistical application of Theory

of Constraints – a scheduling system providing planning and controlling methods. Drum-Buffer-

Rope is a relatively simple system and one of its biggest advantages is that it does not require

buy-in at the floor level. Only a higher level buy-in is required for successful implementation.

Enough literature also exist which showcase documented evidence of successful Theory of

Constraints implementation with fast and significant positive results.

4

This paper explores the applicability of Drum-Buffer-Rope to objectively conclude if it is in

fact a practical solution which can deliver high due-date performance even in volatile

environments. It is limited to products which do not require any processing between sewing,

finishing & packing of garments.

1.1. Objectives

Identify the system constraint & develop an exploitation strategy with minimal

changes in current working.

Implement drum-buffer-rope scheduling

Design a constructive control mechanism to monitor drum-buffer-rope

The stability that the system described in this paper can deliver should be used as a

cornerstone to drive a process of ongoing improvement which not only aims to create more

money for the manufacturer but also to develop and evolve production systems while providing

employees with better working conditions and higher wages. Operational stability is the first

hurdle stopping manufacturers from looking beyond seasonal profits and must be addressed

immediately.

5

02. Review of Literature

6

The manufacturing of apparel has evolved to include the application of various production

systems depending on the nature of business and type of product. In the pursuit of running

excellent operations, organizations have implemented various production systems and adapted

different philosophies with varying levels of success and failure. Most of such efforts have been

driven by a primary focus on reducing costs through an emphasis on increasing local

improvements. However, a global focus on improving the overall system is required based on a

logical operating principle with supporting mechanisms to govern local improvements. Before

local improvements can be effectively made, the system must be stabilized on a reliable

operating mechanism. The Theory of Constraints Drum-Buffer-Rope Scheduling applied as the

operating principle to design the overall production system can provide such a system along with

the power of focus. Instead of improving many areas simultaneously, improvement efforts can be

logically directed to the problem areas that affect the system the most. Once the area of focus is

identified, local improvements based on Lean tools and principles can lead to effective and

meaningful results. The following review illustrates the evolution of assembly lines and pull-

systems highlighting their underlying principles and examines literature on the Theory of

Constraints, Drum-Buffer-Rope scheduling, V-A-T plant analysis and the fundamentals of Lean

manufacturing.

2.1 Production Concepts & Applications

The perception of apparel manufacturing is often limited to its certain functions such as

Merchandising, Cutting, Sewing and Finishing. Within this context, the larger picture is often

missed. Made-to-Order apparel manufacturing must be seen as a whole system and not just a

collection of individual departments and it’s most important measure should be Due-Date

Performance. The following excerpts highlight the principles governing manufacturing systems

7

and lead to the rationale of why a Theory of Constraints Drum-Buffer-Rope application can be

very effective in improving the Due-Date Performance of such systems.

“The manufacturing industry has been shaped by two great thinkers, Henry Ford and Taiichi

Ohno. Ford revolutionized mass production by introducing the flow lines. Ohno took Ford’s

ideas to the next level in his Toyota Production System (TPS), a system that forced the entire

industry to change its grasp of inventory from an asset to a liability. Ford’s starting point was

that the key for effective production is to concentrate on improving the overall flow of products

through the operations. If transportation were perfect and an even flow of materials could be

assured, it would not be necessary to carry any stock whatsoever. The carloads of raw materials

would arrive on schedule and in the planned order and amounts, and go from the railway cars

into production. That would save a great deal of money, for it would give a very rapid turnover

and thus decrease the amount of money tied up in materials.”

“Ford’s efforts to improve flow were so successful that, by 1926, the lead time from

mining the iron ore to having a completed car, composed of more than 5,000 parts on the train

ready for delivery, was 81 hours. Eighty years later, no car manufacturer in the world has been

able to achieve, or even come close, to such a short lead time.”

“Flow means that inventories in the operation are moving. When inventory is not

moving, inventory accumulates. Accumulation of inventory takes up space. Therefore, an

intuitive way to achieve better flow is to limit the space allowed for inventory to accumulate. To

achieve better flow, Ford limited the space allotted for work-in-process between each two work

centers. That is the essence of the flow lines, as can be verified by the fact that the first flow lines

8

didn’t have any mechanical means, like conveyers, to move inventory from one work center to

another.”

“The daring nature of Ford’s method is revealed when one realizes that a direct

consequence of limiting the space is that when the allotted space is full, the workers feeding it

must stop producing. Therefore, in order to achieve flow, Ford had to abolish local efficiencies.

In other words, flow lines are flying in the face of conventional wisdom; the convention that, to

be effective, every worker and every work center have to be busy 100% of the time. One might

think that preventing resources from working continuously will decrease throughput (output) of

the operation. That undesirable effect might have been the result if Ford would have been

satisfied with just limiting the space. But, there is another effect that stems from restricting the

accumulation of inventory. It makes it very visible to spot the real problems that jeopardize the

flow – when one work center in a line stops producing for more than a short while, soon the

whole line stops. Ford took advantage of the resulting clear visibility to better balance the flow

by addressing and eliminating the apparent stoppages. The end result of abolishing local

efficiencies and balancing the flow is a substantial increase in throughput. Henry Ford achieved

the highest throughput per worker of any car manufacturing company of his time.” 01.A

Like Ford, Ohno’s primary objective was improving flow – decreasing lead time – as

indicated in his response to the question about what Toyota is doing:

“All we are doing is looking at the time line from the moment the customer gives us an order

to the point when we collect the cash. And we are reducing that time line…”

Ohno established the Toyota Production System to achieve flow by focusing on removing

wastes. In his works, Ohno gives full credit for the underlying concepts to Ford. The original

9

emphasis on the importance of identifying and removing wastes was stated by Ford in a chapter

titled “Learning from Waste” 02 –

“Conserving our natural resources by withdrawing them from use is not a service to the

community. That is holding to the old theory that a thing is more important than a man. Our

natural resources are ample for all our present needs. We do not have to bother about them as

resources. What we do have to bother about is the waste of human labor.”

“Take a vein of coal in a mine. As long as it remains in the mine, it’s of no importance,

but when a chunk of that coal has been mined and set down in Detroit, it becomes a thing of

importance, because then it represents a certain amount of the labor of men used in its mining

and transportation. If we waste that bit of coal - which is another way of saying if we do not put

it to its full value — then we waste the time and energy of men. A man cannot be paid much for

producing something which is to be wasted.”

“My theory of waste goes back of the thing itself into the labor of producing it. We want to

get full value out of labor so that we may be able to pay it full value. It is use — not conservation

— that interests us. We want to use material to its utmost in order that the time of men may not

be lost. Material costs mean nothing. It is of no account until it comes into the hands of

management.”

“Saving material because it is material, and saving material because it represents labor might

seem to amount to the same thing. But the approach makes a deal of difference. We will use

material more carefully if we think of it as labor. For instance, we will not so lightly waste

material simply because we can reclaim it — for salvage involves labor. The ideal situation is to

have nothing to salvage.”

10

“We have a large salvage department, which apparently earns for us twenty or more million

dollars a year. But as that department grew and became more important and more strikingly

valuable, we began to ask ourselves: Why should we have so much to salvage? Are we not

giving more attention to reclaiming than to not wasting?”

“And with that thought in mind, we set out to examine all our processes. A little of what we

do in the way of saving manpower by extending machinery has already been told, and what we

are doing with coal, wood, power and transportation will be told in later chapters. This has to do

only with what was waste. Our studies and investigations up to date have resulted in the saving

of 80,000,000 pounds of steel a year that formerly went into scrap and had to be reworked with

the expenditure of labor. This amounts to about three million dollars a year, or, to put it in a

better way, to the unnecessary labor on our scale of wages of upward of two thousand men. And

all of that saving was accomplished so simply that our present wonder is why we did not do it

before.”

Ohno expanded this understanding to modern manufacturing and identified seven wastes,

whose elimination forms the backbone of Lean thinking. Ohno introduced these wastes in the

section titled “Complete Analysis of Waste” 03-

“Modem industry seems stuck in this way of thinking. A person in business may feel uneasy

about survival in this competitive society without keeping some inventories of raw materials,

work-in-process, and products.”

“This type of hoarding, however, is no longer practical. Industrial society must develop the

courage, or rather the common sense, to procure only what is needed when it is needed and in the

amount needed.”

11

“This requires what I call a revolution in consciousness, a change of attitude and viewpoint

by business people. In a period of slow growth, holding a large inventory causes the waste of

overproduction. It also leads to an inventory of defectives, which is a serious business loss. We

must understand these situations in-depth before we can achieve a revolution in consciousness.”

“When thinking about the absolute elimination of waste, keep the following two points in

mind”:

1. Improving efficiency makes sense only when it is tied to cost reduction. To achieve

this, we have to start producing only the things we need using minimum manpower.

2. Look at the efficiency of each operator and of each line. Then look at the operators as

a group, and then at the efficiency of the entire plant (all the lines). Efficiency must

be improved at each step and1 at the same time, for the plant as a whole.

“Let’s say, for instance, one production line has 10 workers and makes 100 products per day.

This means the line capacity is 100 pieces per day and the productivity per person is 10 pieces

per day. Observing the line and workers in further detail, however, we notice overproduction,

workers waiting, and other unnecessary movements depending on the time of day.”

“Suppose we improved the situation and reduced manpower by two workers. The fact that 8

workers could produce 100 pieces daily suggests that we can make 125 pieces a day, increasing

efficiency without reducing manpower. Actually, however, the capacity to make 125 pieces a

day existed before but it was being wasted in the form of unnecessary work and overproduction.”

12

“This means that if we regard only work that is needed as real work and define the rest as

waste, the following equation holds true whether considering individual workers or the entire

line: Present Capacity = Work + Waste”

“True efficiency improvement comes when we produce zero waste and bring the percentage

of work to 100 percent. Since, in the Toyota production system, we must make only the amount

needed, manpower must be reduced to trim excess capacity and match the needed quantity.”

“The preliminary step toward application of the Toyota production system is to identify

wastes completely”:

1. Waste of overproduction

2. Waste of time on hand (waiting)

3. Waste in transportation

4. Waste of processing itself

5. Waste of stock on hand (inventory)

6. Waste of movement

7. Waste of making defective products

“Eliminating these wastes completely can improve the operating efficiency by a large

margin. To do this, we must make only the quantity needed, thereby releasing extra manpower.

The Toyota production system clearly reveals excess manpower. Because of this, some labor

union people have been suspicious of it as a means of laying off workers. But that is not the

idea.”

13

“Management’s responsibility is to identify excess manpower and utilize it effectively.

Hiring people when business is good and production is high just to lay them off or recruiting

early retirees when recession hits are bad practices. Managers should use them with care. On the

other hand, eliminating wasteful and meaningless jobs enhances the value of work for workers.”

“Ohno was fully aware that there were too many things that can be improved, that without a

way to focus the process improvement efforts it would take too long to balance the flow. The

Kanban system provided him such a way. Between each two work centers and for each

component separately, the accumulation of inventory is limited by setting a certain number of

containers and the number of units per container. These containers, like every container in every

industry, also contain the relevant paperwork. But, one page of the paperwork – usually a card

(kanban in Japanese) – a page that specifies only the component code name and the number of

units per container, is treated in an unconventional way. When the succeeding work center

withdraws a container for further processing that card is not moved with the container, rather it is

passed back to the preceding work center. This is the notification to that work center that a

container was withdrawn, that the allotted inventory is not full. Only in that case is the preceding

work center allowed to produce (one container of parts specified by the card). In essence the

Kanban system directs each work center when and what to produce but, more importantly, it

directs when not to produce. No card – no production. The Kanban system is the practical

mechanism that guides the operation when not to produce prevents overproduction. Ohno

succeeded to expand Ford’s concepts by changing the base of the mechanism from space to

inventory.” 01.B

The underlying concepts adopted by Ford and Ohno stated as the concepts of supply chains -

14

1. Improving flow (or equivalently lead time) is a primary objective of operations.

2. This primary objective should be translated into a practical mechanism that guides the

operation when not to produce (prevents overproduction). Ford used space; Ohno

used inventory.

3. Local efficiencies must be abolished.

4. A focusing process to balance flow must be in place. Ford used direct observation.

Ohno used the gradual reduction of the number of containers and then gradual

reduction of parts per container.

The Limitations of TPS -

1. TPS is restricted to relatively stable environments,

2. Most environments suffer from instability, and

3. Relatively unstable environments have much more to gain from better flow than even

stable environments.

“The most intuitive base for the mechanism to restrict over-production is not space or

inventory but time – if one wants to prevent production ahead of time one should not release the

material ahead of time. Using time as the base is not only more intuitive and, therefore, more

easily accepted by the shop floor, it has an advantage that makes it suitable for unstable

environments – it is much less sensitive to disruptions in flow. The robustness of the time-based

mechanism stems from the fact that it directly restricts the overall amount of work in the system

rather than doing it through restricting the amount of work between each two work centers. In

flow lines or Kanban-based systems the allotted inventories between work centers is restricted to

the bare minimum (usually corresponding to much less than one hour of work). Therefore, when

15

a work center is down for more than a short while the succeeding work centers are almost

immediately starved for work and the preceding work centers are “blocked” from working.

When, for any of the work centers, the accumulated time consumed by starvation and blockage is

more than the excess capacity of that work center, the throughput of the company is reduced. The

sensitivity of flow lines and Kanban-based systems stems from the fact that a disruption that

occurs in one work center consumes capacity also from the upstream and downstream work

centers – a phenomenon that (almost) doesn’t exist for the time-based systems since the work,

once released to the floor is not artificially restrained. The time based application of the supply

chains concept is the Theory of Constraints Drum-Buffer-Rope system.” 01.C

“Many claims were made regarding the benefits of TOC. These included: increased

Throughput (i.e., Revenue—Totally Variable Costs), reduced inventories, and reduced lead-

times, which in turn would lead to higher sales, and improvements in profits, quality, and

customer satisfaction. We felt it would be useful to collect together and analyze the actual

reported data on the benefits of TOC, to verify or disprove these claims. The literature search

identified over 100 case studies or vignettes that contained information on the results of

applications of TOC. Not all of these provided quantitative data on the results of applying TOC.

In total, we were able to collect quantitative data on the application of TOC to 82 different

companies. The types of organizations covered by these cases varied from giant multi-national

corporations and industry leaders like Boeing and General Motors, to military organizations like

the U.S. Air Force to small town bakeries.” 04

The results of the analysis of reported changes in operational and financial performance,

resulting from the application of TOC, are summarized below:

16

Lead Time Mean Reduction – 70%

Inventory Level Mean Reduction – 49%

Revenue/Throughput/Profit Mean Increase – 76%

The export oriented apparel manufacturing industry works in a make-to-order environment.

A classical measure of the performance of systems in such an environment is due-date

performance. Previous literature has demonstrated that due-date performance can be improved

by effective management of order release, working priorities, and bottlenecks.

“Our experimental study examined why high due-date performance is difficult to achieve.

Thirty teams participated in the first experiment and five teams in the second experiment

(involving a total of 245 people). Our results support the notion that in most cases, variability is

not the root cause of poor due-date performance. Poor due-date performance is caused by the

mode of managing operations, including the following phenomena” 05:

1. Over-promising, or setting order due dates that fail to consider the planned load of the

constraint;

2. Not choking the order release, which results in too many orders on the shop floor due

to excessively early release, a situation that masks priorities, promotes local optimal

behavior, prolongs lead time, and significantly disrupts due-date performance;

3. Failure to manage priorities, resulting in hectic priorities that create chaos on the floor

and lead to late orders.

“Based on our findings, due-date performance improvement programs should first focus on

improving the management of production planning and execution, instead of reducing

variability.” 05

17

Drum-Buffer-Rope, a Theory of Constraints planning & scheduling solution is a time-based

application of the supply chains concept. The fundamental assumption is that within any plant

there is one or a limited number of scarce resources which control the overall output of that

plant. This is the “drum” which sets the pace of all other resources. In order to maximize the

output of the system, planning and execution behaviors are focused on exploiting the drum,

protecting it against disruption through the use of “time buffers” and synchronizing or

subordinating all other resources and decisions to the activity of the drum through a mechanism

that is akin to a “rope”. 06

Figure 2.1 Relationship between management time required and the time buffer size. 01.D

18

2.2. Theory of Constraints

It has been said;; “Tell me how you will measure me, and I will tell you how I will behave”

07.A The whole internal business performance measurement system is based upon local

optimization, either in the form of departmental utilization/efficiency measures or as

departmental cost/profit performance measures - or both. It takes some conscious effort to

realize that the formalization of local efficiency measures through the activities of scientific

management is only about 100 years old. 08 Its assumed that the total performance of the system

is the sum of all the local performances. In fact it is so common that it is not even given much

thought. This approach then is the reductionist/local optima approach; departmental cost or

efficiency is just a symptom or an output of this method. 09

“Living systems have integrity. Their character depends on the whole. The same is true for

organizations; to understand the most challenging managerial issues require seeing the whole

system that generates issues.” 10 It should be known what the system is that one is dealing with,

where does it start, and where does it end. It should be known what the system exists for, and

how to measure progress towards the reason for its existence. Scheinkopf expresses this as 11:

1. Define the system and its purpose.

2. Determine the system’s fundamental measurements.

The organization in fact defines the measurements rather than the other way around – the

measurements define the organization. Margaret Wheatley is more articulate. She argues that in

too many organizations “… the measures define what is meaningful rather than letting the

greater meaning of the work define the measures. As the focus narrows, people disconnect from

any larger purpose and only do what is required of them.” 10

19

The fundamental measures for a system must be determined and then ensured that

performance measures are subordinated to these fundamental measures. “Not just any

measurements, but measurements that will enable us to judge the impact of a local decision on

the global goal.” 07.B

“Measurements are a direct result of the chosen goal. There is no way that we can select a

set of measurements before the goal is defined.” The measurements should enable the judgment

whether a local decision has an impact on the global goal. 07.C

In a commercial organization the fundamental measures are defined by the following

questions 07.D:

1. How much money is generated by the company?

2. How much money is captured by the company?

3. How much money is spent to operate it?

Goldratt calls these 3 measures; Throughput, Inventory, and Operating Expense. These are

often shortened to T, I, and OE and are defined as follows 07.E:

1. Throughput is the rate at which the system generates money through sales.

2. Inventory is all the money that the system invests in purchasing things which it intends to

sell.

3. Operating expense is all the money the system spends in order to turn inventory into

throughput.

20

2.3. V/A/T Analysis & Synchronous Manufacturing

Serial processes where there are dependencies between one step and another are a relatively

new phenomenon. Prior to the industrial revolution such organizations did not exist. Since the

beginning of industrial revolution many have done little more than become larger and more

complicated as they take advantage of economies of scale and economies of scope. 08

In a process where similar machines, or people who are doing similar operations, are grouped

together, work moves in a sequence between these specialist areas, sometimes flowing back the

way it came to a previous area before continuing on in the process. This layout is known as a

“job shop.” A simple example might be a small engineering firm. Each job in the process could

be unique or it could be a repetition of a standard design. Each job could consist of single unit or

a batch of many units. 09

At the other end of the scale from the job shop is a “flow shop.” Here machinery or people

are sequenced throughout the plant in the order that most work will require. Again the work

might be unique or a repetition of a standard design. Each job could consist of a single unit or a

batch of many units. 09

Furniture companies that produce for the retail trade are usually a flow shop. Tool bit

manufacturers are another example. So too are electronics and automotive, however, as the

diversity of products decreases and the batch size increases the flow in parts of these flow shops

becomes more and more continuous. Ultimately these parts may become a dedicated flow shop

– one flow or process for one product or product family. 09

So, why can’t these flow shops become truly continuous, like a pulp and paper plant, or a

petrochemical process? The answer is that the items in the process are discrete, made of

21

individual parts, rather than non-discrete like a liquid or a crushed ore. In fact many of the truly

continuous industries are in the primary or extractive industries – pulp and paper, petrochemical,

and dairy. Most of these industries benefit from economies of scale and are capital intensive

with a concomitant reduction or replacement of labor. 09

Within the discrete product job shop and flow shops there are 3 basic topologies which

describe the flow of material within the process. V/A/T plant classification was developed

primarily by Eli Goldratt. Around 1980, while running a consulting organization called Creative

Output, Goldratt noticed that manufacturing plants in very different industries seemed to have

similar characteristics and problems. From this experience he developed the V/A/T classification

system. 12

Product flow diagrams are used to determine the structure of a plant. Three specific

categories of points are of special interest in product flow diagrams: divergence points,

convergent assembly points, and divergent assembly points. Divergence points are steps in the

product flow at which material may be transformed into two or more distinctly different

materials. Convergent assembly points are points at which two or more component parts are

assembled to form a single parent item. Divergent assembly points occur when a number of

common component parts may be combined or assembled in a variety of ways to form a large

number of possible parent items. The product flow diagram of a specific manufacturing

environment may include divergence points, convergent assembly points, and divergent

assembly points. However, one of these three categories will usually dominate. This observation

led to the development of three basic plant classification categories: V-plants, A-plants and T-

plants. 13

22

Product flow diagrams for V-plants are characterized by divergence points throughout the

production process. In such plants, a single piece of material can be increasingly transformed at

each divergence point into a very large number of distinctly different end items. The general

shape of the product flow diagram resembles the letter "V," hence the designation V-plant. 13

A-plants are characterized by convergent assembly points throughout the process. In such

plants, a large number of purchased or fabricated component parts and materials are combined to

form subassemblies that are used to build unique end products. Several levels of subassemblies

are typically necessary before final assembly can be performed. The typical product flow

diagram for a plant exhibiting this basic convergence process resembles a pyramid. Hence, the

designation A-plant. 13

T-plants are dominated by a major divergent assembly point at final assembly, where many

different end items are assembled from a relatively limited number of component parts, many of

which are common to numerous end items. In T-plants, the critical resource and product

interactions take place at final assembly, where the product structure expands to yield a large

variety of assembled products. The narrow component base, coupled with the very expansive top

portion representing the end item configurations, give rise to a product flow diagram that

resembles the letter "T." 13

Both the Ford production system and the Toyota production have a commonality in their

implicit treatment of the constraint or slowest step. Both systems seek to synchronize the

remainder of the system to the slowest step, either by a physical moving line or by kanban

cards. The constraint, in-turn, can be synchronized to the external market demand.

23

Exploitation of these systems occurs via “line balancing” and also by inventory reduction in

just-in-time.

The Theory of Constraints production solution, drum-buffer-rope, in contrast is explicit in its

recognition of the existence of constraints. As such, only the key control points of raw material

release, points of convergence or divergence, the constraint, and shipping need to be “tied”

together by the logistical system. The mechanism to tie the points together is a time-phased

schedule.

Because drum-buffer-rope explicitly recognizes the constraint and exploits it’s capability to

the full, drum-buffer-rope is able to operate at any product volume or level of diversity.

Umble and Srikanth recognize the similarities of the Ford production system, Toyota

production system and drum-buffer-rope under the term synchronous manufacturing. In this

classification, the Ford production system and the Toyota production system can be viewed as

partial implementations, or sub-sets, of synchronous manufacturing and drum-buffer-rope as a

full set of the capabilities. 14

2.4. Drum-Buffer-Rope Scheduling

Senge described the “where we are now” as the current reality, and the “where we want to be

in the future” as the vision. 15 He noted that if there was no gap between the current reality and

the vision, then there would be no need to move toward the vision. The gap between the two

becomes a source of creative energy which he termed “creative tension.”

But that doesn’t actually help to move forward. In fact Senge notes that “creative tension

often leads to feelings or emotions associated with anxiety, such as sadness, discouragement,

24

hopelessness, or worry.” Senge described this as “emotional tension.” The key point is not to

confuse creative tension with emotional tension, otherwise we predispose ourselves to lowering

our vision. 15 We need a process of change to ensure that we move from where we are now to

where we want to be in the near future.

Goldratt briefly outlined a process of change in 1990. 16 He characterized it as follows;

1. What to change.

2. What to change to.

3. How to cause the change.

Goldratt furnished a focusing process in the earliest versions of The Goal, however, it was

implicit. In later editions it was made explicit as the five focusing steps. The five focusing

steps, exactly as in the original verbalization, are as follows 17:

1. Identify the system’s constraints.

2. Decide how to exploit the system’s constraints.

3. Subordinate everything else to the above decision.

4. Elevate the system’s constraints.

5. If in the previous steps a constraint has been broken, Go back to step 1, but do not allow

inertia to cause a system constraint.

Proper subordination is the key to effective implementation of Theory of Constraints. Proper

subordination means that the non-constraints only do what is required to ensure maximum

exploitation of the constraint. It needs to be ensured that the parts are subordinated to the whole,

or more correctly in larger-scale enterprises, that the subsystems are subordinated to the system.

25

Once an exploitation plan has been decided upon, there are two ways to deviate from this

plan. 13 Deviating from the plan means improper subordination and consequently less than fully

effective exploitation. Deviation from the plan results from:

1. Not doing what was supposed to be done.

2. Doing what was not supposed to be done.

Drum-buffer-rope is the Theory of Constraints production application. It is named after the 3

essential elements of the solution; the drum or constraint or weakest link, the buffer or material

release duration, and the rope or release timing. The aim of the solution is to protect the weakest

link in the system, and therefore the system as a whole, against process dependency and variation

and thus maximize the systems’ overall effectiveness. The outcome is a robust and dependable

process that allows more production with fewer inventories, less rework/defects, and better on-

time delivery.

Drum-buffer-rope however is really just one part of a two part act. If drum-buffer-rope is the

motor for production, then buffer management is the monitor. Buffer management guides the

way in which the motor is tuned for peak performance.

In determining the buffer, the rule of thumb to apply is to halve the existing lead time. 18 To

this buffer, a second rule of thumb is applied. The buffer is divided into zones of one third each.

19 Most work is expected to be completed in the first 2 thirds and be waiting in front of the

constraint for the last third of the buffer time.

For all practical purposes the “time buffer” is the time interval by which the release of work

is predated, relative to the date at which the corresponding constraint’s consumption is

26

scheduled. 7.8 The zones equate to time allocated in the plant to protecting an operation whose

position and function is critical to the timeliness and output of the whole process. The zones do

not equate to the position of work in the plant.

“The reason buffers are defined as the whole lead time and not just the safety portion is that

in most manufacturing environments there is a huge difference between the sum of the net

processing times and the total lead time. When we review the net processing time of most

products, we find it takes between several minutes and an hour per unit. But the lead time may

be several weeks, and even in the best environments several days. Consequently, each unit of

product waits for attention somewhere on the shop floor for a much longer time than it actually

takes to work on it.” “So it makes sense not to isolate the net processing time, but to treat the

whole lead time as a buffer – the time the shop floor needs to handle all the orders it must

process.” 21.A

The above paragraphs describe the operations system in Drum-Buffer-Rope. To ensure its

stability, a monitoring system is also required. This is done through buffer management. Buffers

and their purpose have already been discussed, however a mechanism is required to interpret and

utilize the information that they can provide. And in order to do that, their impact must be

divided into two distinct functions. They are as follows;

1. Local Control - the day-to-day exception reporting that indicates when there may be a

potential due date violation.

2. Global Feedback - longer term trend-reporting that suggests a particular buffer needs to

be resized to be fully effective.

27

Buffer management is crucial; it filters important signals from the day-to-day noise of the

system thereby alerting the potential problems before they become real problems and it provides

a self-diagnosis that neither too much and nor too little protection is made available for each

case. The self-diagnosis feeds back into our configuration and guides improvements in the

overall dynamics of the implementation.

Thus, control is also implemented along with planning, but it is local and within the context

of the overall design of the implementation. Schragenheim & Dettmer have an important

definition of control 21.B:

“A reactive mechanism that handles uncertainty by monitoring information that indicates a

threatening situation and taking appropriate corrective action before the threat is realized.”

Consider the rock and water analogy. The water level corresponds to the inventory level,

while the rocks are the problems disturbing the flow. There are many rocks at the bottom of the

river and it takes time and effort to remove them. The question is which rocks are important to

remove. The answer is given by reducing the water level; those rocks which emerge above the

water are the ones that should be removed. The drum-buffer-rope operating model controls the

inventory level through time buffers while Buffer management provides a constructive control

mechanism which makes it possible to focus on areas which cause problems in the productivity

of the system. This Theory of Constraints application can provide operating stability with high

due-date performance in made-to-order apparel manufacturing firms. This stability is the most

basic requirement to drive any further improvements which add to the bottom line and are

sustainable.

28

2.2 List of References

1. Goldratt (2009), 334, 335, 341, 339 2. Ford (1926), 89 3. Ohno (1988), 18-20 4. Mabin & Balderstone (2000), 10-12 5. Lee, Hwang, Wang & Lee (2009), 42 6. Woeppel (2000), 1 7. Goldratt (1990), 26, 10, 14, 19, 23 8. Johnson & Kaplan (1987), 217, 49-57 9. Youngman (2005) 10. Wheatley & Kellner-Rogers (1999) 11. Scheinkopf (1999), 23-24 12. Cox & Spencer (1998), 101-128 13. Umble & Umble (1999) 14. Umble & Srikanth (1995), 211-255 15. Senge (1990), 150-151 16. Goldratt, E.M (1990), 3-21 17. Goldratt & Cox (1986), 307 18. Goldratt (1997), 149 19. Stein (1996), 143 20. Schragenheim & Dettmer (2000), 123-135, 176

* Citations for the above mentioned authorities are provided in chapter 09: Bibliography

29

03. Methodology

30

This paper explores the applicability of a Theory of Constraints Drum-Buffer-Rope operating

mechanism for production in a low-volume/high-mix made-to-order apparel manufacturing

environment to establish a proactive planning & constructive control system that ensures high

due-date performance along with higher throughput, lower inventory and lower operating

expense.

3.1. Scope of Research

The research is limited to scheduling only production processes after the purchase of raw

material; grey fabric in this particular case. Purchase of trims & accessories is not explicitly

handled and is limited to monitoring with respect to deadlines for getting materials in-house.

3.2. Assumptions

Purchase of raw materials is still largely based on the archaic1 notion of buying stocks when

prices are low and buying restrictively when prices are high. Due to this sporadic nature of raw

material purchases, it has not been included in the planning & control system described in this

paper. It has been assumed that raw material i.e. Grey Fabric is readily available whenever it is

required for further processing. Trims & accessories are also assumed to be available for

production as and when required.

3.3. Constraints

Theory of Constraints advocates that each system is a chain of dependent processes. The

strength of this chain is governed by the weakest link, the bottleneck or constraint. As discussed

1 “We have carefully figured, over the years, that buying ahead of requirements does not pay--that the gains on one purchase will be offset

by the losses on another, and in the end we have gone to a great deal of trouble without any corresponding benefit. Therefore in our buying we

simply get the best price we can for the quantity that we require. We do not buy less if the price be high and we do not buy more if the price be

low.” – Henry Ford in “My Life & Work”, 1922

31

earlier in section 2.4, identifying this constraint is the first step to any Theory of Constraints

application.

3.3.1. Identifying the Constraint

A cursory glance at the various departments to identify any potential bottlenecks revealed

that few processes had much more capacity than certain others. Four departments/processes in

particular emerged as potential constraints and were studied to find if any one of them could be

conclusively considered as the constraint.

The daily outputs of these four processes were recorded for a period of 26 days. During this

period, 85% of the output constituted of three different styles with shipment dates varying within

a week from one another. All three styles were floated on the floor considerably simultaneously.

However, to ease out any slight fluctuations in the output of the processes due to variation in

styles a 3 day moving average was used for comparing them. This comparison is illustrated in

appendix A.

The above comparison revealed that a single constraint does not exist. Instead, all of the four

processes exhibited close to equal probability of becoming the bottleneck which over a period of

time led to travelling constraints i.e. the constraint laid at a different process every day. Since an

application of Drum-Buffer-Rope scheduling necessitates the existence of a definite constraint,

this dilemma prompted the need to design a constraint.

3.3.2. V/A/T and 5 Why Analysis

V/A/T analysis has been discussed earlier in section 2.3. In the pursuit of designing the

constraint, a V/A/T analysis was conducted to figure out the logical structure of the plant. The

32

divergence and convergent points of materials were plotted and the entire structure is presented

in appendix B. This analysis revealed that there were complex dependencies in the four

processes causing travelling constraints as discussed in section 3.3.

A 5-Why analysis was conducted on these four processes to highlight the existence of

wastes2 and to determine the root causes of problems through cause and effect logic. The

tabulation of the analysis along with a Pareto analysis of the root causes are presented in

appendices C.1 to C.5.

The above analysis suggested that the departmental barriers within the four processes should

be broken and instead of a serial structure, the four processes should be combined into a

continuous process. Creating such a continuous process of consolidated functions could also

disentangle the logical structure of the plant by creating parallel assembly processes thus creating

a definitive T plant as shown in appendix D. Essentially, the 4 serial processes causing travelling

constraints were broken down into smaller consolidated parallel processes creating manageable

independent constraints which would act as drums3 to base the drum-buffer-rope scheduling

system on.

3.3.3. Design of Constraint

Once established that the constraint must be designed by creating consolidated processes, the

feasibility of such an environment was studied. The four processes considered for consolidation

were sewing, thread cutting, finishing and packing.

2 Production Wastes as described in section 2.1

3 A Drum is a constraint in the system which determined the pace of the overall system.

33

Thread cutting was considered to be a wholly non-value adding process. Operators in sewing

stage should cut the threads after finishing each operation from the root so as to eliminate the

need for a separate thread cutting process. To test its feasibility, a time study was conducted on

different operations of a style to identify the average increase in operation time due to this added

responsibility (appendix E). The two approaches – incorporated thread cutting & separate thread

cutting were compared on 3 measurements to conclusively determine if eliminating thread

cutting as a separate process was truly beneficial (appendix F).

With the thread cutting process eliminated, sewing, finishing & packing remained to be

consolidated. Lean production has the potential to create a high velocity cell but the environment

of the plant which involves high labor turnover, seasonal demand and very diverse product mix

limited4 its application. However, a virtual consolidation was still possible. This did not require

any major spatial rearrangement, only a reconfiguration of how material was moved between

these processes. This was achieved by creating two assembly lines in the finishing floor which

could handle finishing & packing on a continuous basis. Each such line was dedicated to work

which it received from a particular sewing line on an hourly basis.

Two such virtually consolidated drums were created and six orders were executed on them

from the point of grey material release to shipment. These pilot runs were considered as the basis

for creating a case for the superiority of drum-buffer-rope scheduling.

3.4. Applying Drum-Buffer-Rope

Drum-Buffer-Rope has been discussed in section 2.4. It is the operating principle, the motor

which drives production. It was applied through the steps described in the following sections.

4 Limitation of TPS as discussed in section 2.1

34

3.4.1. Establishing Time Buffers

The buffer is the time from the release of material to the time it is due at the drum. As a rule

of thumb, this time is established by halving the present lead time between these two points. The

lead times were determined for various product routings in order to arrive at the time buffer for

drum-buffer-rope scheduling. These times were determined by tracking certain orders as they

progressed through production (appendix G.1 to G.9) and finding the median lead time for

outsourced processes through analysis of historical data.

This time buffer protects against variation in the processes before the drum. To protect

against any variations inside the drum, another buffer called the shipping buffer was used. This

time buffer was the time from the end of the drum to shipping.

3.4.2. Creating a Drum Schedule

For each of the two drums, specific schedules for executing the six orders were created. In

order to create the schedule, the work content of the product was required. In order to determine

the robustness of new system, two approaches were applied to derive the work content:

1. Time study was employed to arrive at a scientific estimate of the work content.

2. Intuition of line masters was used to arrive at average hourly output estimates.

This drum schedule determined the material release for these orders by deducting the time

buffers from the due date at the drum. This link between material release and drum schedule is

known as the rope which prevents excess inventory in the factory.

35

3.4.3. Buffer Management

Buffer management is the monitoring arm of drum-buffer-rope. It is the throttle which keeps

the drum-buffer-rope motor running, tweaking it whenever necessary. It is executed by dividing

the time buffer into three equal zones and monitoring released orders accordingly. It has been

described in section 2.4.

The orders which reach the red zone are assessed. The problem for their lateness is identified

and recorded. At the end of the pilot runs, a Pareto analysis of these occurrences was done to

identify problem areas. Such analysis provides focus to direct any improvement efforts at non-

constraints.

An analysis on the buffer status of all the orders was also done to check if the time buffers

established were less, sufficient or too generous. This allows scientific base gradual reduction of

work-in-process.

3.4.4. Comparison of Existing & Proposed Systems

An objective comparison was made between the existing and proposed systems. This

comparison, amongst others consists of the following Theory of Constraints measurements:

1. Throughput - Throughput is the rate at which the system generates money through sales.

2. Inventory - Inventory is all the money that the system invests in purchasing things which

it intends to sell.

3. Operating Expense - Operating expense is all the money the system spends in order to

turn inventory into throughput.

36

These measures were would be valid when the entire operation is run on drum-buffer-rope.

Since the implementation presented in this paper was limited to pilot runs on two drums, it could

not be compared to the ongoing system on these measures. Thus the comparison was made on

lead times and on-time-in-full deliveries.

The methodology is largely based on generic principles but had to be configured to a certain

degree in order to be valid in the environment of the system of implementation. Overall, the

methods described above can easily be replicated at any other made-to-order apparel

manufacturing firm.

37

04. Constraints

38

Businesses are run by entrepreneurs. Entrepreneurs are driven by a sense of purpose. In the

realm of small and medium scale apparel manufacturers in the country who export to almost all

major markets in the world, this purpose is limited to making monetary gains. With cheap labor

available, operational practices have rarely evolved to reflect the technology and knowledge

available in the new century. A survey of garment factories conducted in the NCR region

presents a sorry state of factories in one of the more mature readymade garment manufacturing

hubs in the country (Annexure A). It might be the certitude of cheap labor that prevents business

owners to look beyond profits and invest on people, but this condition might not exist after ten

years. The cost of labor is increasing yet systems in garment factories are not keeping pace.

SMEs in the sector might well be on the verge of obsolescence by the end of the next decade.

This myopia must be eliminated; to keep the business profitable and preserve the economic

benefits this industry services the country.

Ford described the true industrial idea as not to make money but to express a serviceable

idea, to duplicate a useful idea, by as many thousands as there are people who need it. The

industrial idea exists to spread prosperity. As Ford puts it, prosperity is not measured by the bank

balance of the manufacturer but by the comfort of the people at large. Businesses execute this

industrial idea and the ultimate goal of any business, as Goldratt puts it, is to make money in the

present as well as in the future. A truly sustainable business will only exist when it continues to

make money while contributing to increasing the comfort of its people.

What then is stopping apparel SMEs from becoming truly excellent? - The ubiquitous

obsession with costs. This emphasis that management puts on cost leads to management thriving

to improve local efficiencies. The underlying assumption being that improvement in local

efficiencies adds up to increase the global performance of the business. It is this assumption that

39

must be challenged. Goldratt argues that every business is a system and every system has at least

one constraint which determines the overall performance of the system. Consider the system to

be a chain. The local optima approach measures the performance of this chain by its weight.

Increasing the weight of each link increases the overall weight. But this measure is wrong. The

performance of the chain should be determined by its strength, not weight. This strength is

determined by the strength of the weakest link. Thus in a system of dependent processes, its

performance is determined by the weakest process, the constraint. Theory of Constraints works

on this principle and advocates that systems must be managed by their constraints. The following

example illustrates this concept:

Product X is manufactured by starting with Raw Material X and then processing it sequentially through 5

operations using machines A to E respectively. This is the only use that the five machines are put to. The hourly rates for each machine are given in the table.

Operation 1 2 3 4 5

Machine M/C A M/C B M/C C M/C D M/C E Hourly Unit Output Rate 100 80 40 60 90

This begs a number of questions to help answer, "Why manage by constraints?”

Question Answer What is limiting the System?

What is the maximum output per hour of Product X? 40 M/C C

By how much would the output be improved if B was increased to 90? No Improvement M/C C

By how much would the output be improved if C was increased to 50? By 10 M/C C

By how much would the output be improved if C was increased to 70? By 20 M/C D

What effect on the system if M/C A can only manage an output of 90 in one hour? None M/C C

What effect on the system if M/C C can only manage an output of 30 in one hour?

We lose 10 Product X M/C C

What effect on the system if M/C B is allowed to drop to an output of 30 in one hour?

We lose 10 Product X

M/C B for that hour. Note also that the loss cannot be recovered.

40

This paper explores the practical applicability of the Theory of Constraints in a high-

mix/low-volume made-to-order apparel manufacturing environment through its logistical

solution known as Drum-Buffer-Rope Scheduling to deliver high due-date performance with

increased throughput and lower inventories. The first step to execute this Theory of Constraints

application was to identify the system’s constraint.

4.1. Identifying the System’s Constraint

A typical garment manufacturer’s system comprises of the following processes –

Procurement

Cutting

Sewing

Thread Cutting

Finishing

Packing

Dispatch

In addition to the above processes, the plant at which the research was carried out housed a

process of smocking. This plant manufactures women’s dresses, skirts, tops and blouses across a

wide range of printed and dyed fabrics. Grey fabric is purchased in bulk and large stocks are

maintained. This serves the dual purpose of ensuring quality of the raw material as well as

making cost gains due to bulk purchasing at lower prices. They grey fabric is issued to various

printers in nearby districts and to dyers within the city. After the receipt of fabric, it is checked in

the printed fabric warehouse. Checked and approved fabric is issued to cutting which is carried

out on piece rate by contractors. A bird’s eye view of how the company works is shown below.

41

Trims & Accessories

Purchase

Grey Fabric Purchase

Supplier

Reject

Accept

Issue to Printing Printer

Reject

Accept

Trims & Accessories Store Cutting Smocking

Sewing

Finishing

Packing

Dispatch

Figure 4.1 Flowchart of Processes at MA’AM Arts, Jaipur

Check

Check

42

Printing, cutting and smocking are all outsourced processes and do not present a capacity

constraint on the system. Thus, the remaining four departments of sewing, thread cutting,

finishing and packing were examined to find which one of them was the constraint.

The daily outputs of all the four departments were recorded for a period of 26 days from 8th

March to 7th April, 2010. During this period of study, the following orders were produced.

Style No. Description Quantity

UU76786 Women’s Top 42000 AT91007-3 Women’s Top 23500

8R465 8 Tier Skirt 38000 8P520 Women’s Dress 4000 8P255 Women’s Dress 3200 8P264 5 Tier Skirt 2800 8N288 Maxi Dress 2000 Total 115500

Table 4.1 Style Produced between 8th March, 2010 and 7th April, 2010

Source: MA’AM Arts, Jaipur

The above table shows that almost 85% of the total quantity produced in this period

comprised of only 3 styles – UU76786, AT91007-3 and 8R465. To compensate for any

fluctuations in daily outputs, a 3 day moving average was considered to compare the outputs

(appendix A). This revealed the frequency of each department becoming the bottleneck (Figure

4.2). This led to the conclusion that each of the four departments is a potential constraint.

However, a clear constraint does not emerge. This travelling of bottlenecks creates a lot of

variation. To offset this variation, inventory is accumulated leading to longer lead times and

quality problems.

43

Figure 4.2 Shifting Bottlenecks

A 5-Why analysis of the most immediate problems faced in these departments pointed

towards to following aspects -

High Work in Process Inventory

Absence of a Material Release Mechanism

Focus on Improving Local Efficiencies

Quality and Productivity Treated as separate functions

A closer look at these processes through the lens of value5 reveals that these processes should

be carried out continuously. A value-adding ratio of these four processes was calculated to be

1.29% from a value stream map (appendix H). Such a low ratio can be directly attributed to the

5 “Value can only be defined by the ultimate customer. And it's only meaningful when expressed in terms of a specific product, which

meets the customer's needs at a specific price at a specific time." - Womack & Jones, Lean Thinking. For this case, value is considered as any

activity for which the customer is willing to pay for.

0123456789

Sewing Thread Cutting Finishing Packing

Bottleneck Frequency

44

long queue and wait times. This can be eliminated if these four processes were consolidated into

a single process.

These four departments were analyzed through another lens – That of V/A/T analysis.

Goldratt introduced the concepts of V, A & T Plants. He analyzed various manufacturing plants

and concluded that there are essentially 3 plant structures resembling the letters V, A and T.

These structures are created by analyzing divergence and convergence points of products &

processes.

The plant under consideration, MA’AM Arts was analyzed on these lines. The structure is

presented in Appendix B. The plant distributes is processes in the following way –

Cutting is carried out through contractors as already mentioned previously.

9 Sewing lines

Thread Cutting through two contractors with varying capacities as per the plant’s

requirements

2 floors for Finishing and Packing

Although the structure did not reveal a distinct shape, the plant exhibited much of the

characteristics of a T-Plant –

“T-plants are dominated by a major divergent assembly point at final assembly, where many

different end items are assembled from a relatively limited number of component parts, many of

which are common to numerous end items. In T-plants, the critical resource and product

45

interactions take place at final assembly, where the product structure expands to yield a large

variety of assembled products.” 6

4.2. Designing the System’s Constraint

The consolidation of these processes need not be physical. Physical consolidation of these

processes could have employed the principles of lean manufacturing. Although preferable under

stable conditions, physical consolidation was not practicable under the volatile conditions of the

plant under consideration. At this time, the following challenges lay ahead –

A constraint was required to design the Drum-Buffer-Rope application

The four travelling bottlenecks could not have been physically consolidated

A logical consolidation was however very easily possible. This consolidation is explained

later in the next section.

This logical consolidation provides a solution to both the challenges stated above. It

eliminates the problem of travelling constraints by creating truly parallel processes thus revealing

a clear T-Plant structure (Appendix D). Each of these branches creates a set of parallel

constraints. The throughput of these constraints determines the overall throughput of the plant.

Since these constraints set the pace of the plant, they become the drum in the Drum-Buffer-Rope

mechanism as explained in the next chapter.

Wherever the processes required by a garment are broken down and carried out by separate

departments, work-in-process increases and the problem of travelling bottleneck arises. This

arises from the notion of balancing capacities. Balancing capacities can never deliver output as

6 Umble & Umble, 1999

46

per plans due to two important factors – statistical fluctuations and dependent processes. Instead,

the flow of production must be balanced7. This balancing of flow is only possible when the

subsequent processes are not displaced too much from each other. Even if they are not put

physically together, their distance may be reduced on a scale of time. The constraint, in such

fragmented conditions need not be identified but rather designed. The design should arise from

the environmental limitations. This design can be developed by –

1. Measuring the distance between subsequent processes on a scale of time

2. Minimizing this distance to as low as practically possible

The constraint must be designed to be located at the system’s end. Eventually, the constraint

will move into the market. When that happens, demand will become the constraint and the closer

the previously designed constraint is placed to this demand i.e. the shipping schedule, the more

productive the system will become as this configuration would implicate a pull system by its

very nature thus reducing inventory and improving throughput.

4.3. Exploiting the System’s Constraint

Once the constraint has been designed, an exploitation strategy must be devised to extract the

highest throughput from it. In the following paragraphs, the exploitation strategy applied at

MA’AM Arts, Jaipur is described. This strategy is based on the following generic points –

1. Improve the throughput rate of the ultimate output of the consolidated processes.

2. The time between point of inspection and point of operation should be reduced to as

low as possible.

7 Refer the dice game as illustrated in the book “The Goal” by Eliyahu M. Goldratt.

47

3. Any unnecessary steps must be eliminated.

The first irritable observation was a separate thread cutting department. Operators in their

regular course of sewing have to cut thread after each operation. The operator should cut the

threads from the root themselves, thus eliminating the need for separate thread cutting at a later

stage. A time study was performed on a particular style where operators were instructed to cut

the thread themselves (Appendix E). This increased the work content of the garment by only

2.05 minutes, reducing the average hourly output in sewing from 41 to 39 but reducing the lead

time from sewing to finishing from 30 hours to just 10 hours. A cost analysis of thread cutting by

separate department versus thread cutting at source clearly shows that it is more profitable when

the threads are cut by the operators themselves (Appendix F).

Since thread cutting was included as a part of sewing operations, the remaining three distinct

processes of finishing and packing remained to be consolidated. This was achieved by linking a

sewing line with a finishing cell8. The finishing cell was expanded to include packing activities

such as tagging, folding, adding hangers and packing garments into polybags (Appendix I). This

link was logical rather than physical. The sewing line and finishing cell were on different floors.

An inventory of 1 hour’s work was fixed between them. This translated to the hourly output from

the sewing line being fed to the finishing & packing cell.

The finishing & packing cells were much more robust than the sewing lines. Manpower

could easily be added or removed from a cell to balance the flow of units. The only job of the

supervisor was to make sure that the finishing & packing cell was sufficiently manned to

complete one hour’s worth of output from the sewing lines every hour. The hourly target of the

8 Dewan & Sihmar (2010)

48

cell was to produce tagged and folded garments (or hanger, as the case may be) stored size-wise

on racks.

The ultimate output of the designed constraint was to produce packed goods. Garments are

packed in polybags as per customer specifications. It may be any one of the following

configurations.

Packing Polybag (Sizes) Carton (Colorways) Solid Assorted

Solid 1 2 Assorted 3 4

Table 4.2 Types of Packing

1. Solid-Solid – Each carton contains polybags in the same colorway with each polybag

containing a specified number of pieces of the same size.

2. Assorted-Solid – Each carton contains polybags in a specified ratio of colorways with

each polybag containing a specified number of pieces of the same size.

3. Solid-Assorted – Each carton contains polybags in the same colorway with each

polybag containing pieces in a specified size ratio.

4. Assorted-Assorted – Each carton contains polybags in a specified ratio of colorways

with each polybag containing pieces in a specified size ratio.

Thus, the aim of the constraint is to produce items in such a way that they can be packed at

the end of the day. The most common type of packing is type 3. This can be achieved if each line

is fed in batches containing all sizes in ratio. This batch size is subjective and would wary from

product to product. The following rule of thumb was applied to arrive at a batch size –

49

𝐵𝑎𝑡𝑐ℎ 𝑆𝑖𝑧𝑒 = 𝑀𝑢𝑙𝑡𝑖𝑝𝑙𝑒 𝑜𝑓 𝑆𝑖𝑧𝑒 𝑅𝑎𝑡𝑖𝑜 𝑐𝑙𝑜𝑠𝑒𝑠𝑡 𝑡𝑜 𝐸𝑠𝑡𝑖𝑚𝑎𝑡𝑒𝑑 𝐷𝑎𝑖𝑙𝑦 𝑂𝑢𝑡𝑝𝑢𝑡2

Thus, by the end of the day, all sizes would be available for packing in two cycles. An

illustration of this system in explained in greater detail in the table below. The robustness of the

finishing & packing cell was used to keep the bottleneck in the constraint within the sewing line.

This prevented any overproduction downstream of sewing. The timing of the workers in the

finishing and sewing cells was offset by an hour so that the day’s sewing output could be

finished and packed.

Avg. Hourly Output 50 Pieces Feed S M L Feed for Day 400 1 2 3

No. of Lots 2 x 200 A 50 100 50 Size Ratio S:M:L = 1:2:1 B 50 100 50

Time Sewing Finishing/Packing Polybag S M L S M L

09:30 - 10:30 50 - - - - 10:30 - 11:30 50 50 11:30 - 12:30 50 50 12:30 - 01:30 50 50 02:30 - 03:30 50 50 50 03:30 - 04:30 50 50 04:30 - 05:30 50 50 05:30 - 06:30 50 50

6:30 – 07:30 50 50

Table 4.3 – Illustration of production within the drum

A supervisor was made responsible for this entire consolidated constraint. It was his

responsibility to maintain a regular flow of goods through it. This system of working allowed

the constraint to work with lesser inventory and shorter lead times. Much of the queue and

waiting times were eliminated to result in a more robust overall system.

50

05. Drum-Buffer-Rope

51

Manufacturing is at the heart of our industrialized economies. Productivity, thus, is an

indispensible measure. It is the consequence of the production system – the mechanics that turn

the wheels of any manufacturer. Drum-Buffer-Rope is the motor which can drive this production

system and Buffer Management is the throttle to control this motor. How these two Theory of

Constraints logistical solutions are applicable to made-to-order apparel manufacturing is

described in this chapter.

5.1. The Drum

The drum is the constraint in a system. It sets the pace at which the entire system works. The

constraints have been described in the previous chapter. This chapter deals with how these

constraints can be used as drums to run the production system.

Each of the designed constraints is a drum. The system cannot produce any more than what

these drums can produce. Since the drums constitute the throughput of the system, they must

work as best as they can. How these drums were exploited for performance has already been

described in the previous chapter. The focus now is on a broader view of the system.

In a series of dependent processes, statistical fluctuations always occur. These fluctuations

cause variability. In order for the drums to operate continuously without ever being exhausted in

supply from upstream processes, they must be shunned from any variability. This protection is

provided by maintaining buffers before the drums. Traditionally, each process is protected by

maintaining buffers in front of them. However, in drum-buffer-rope, buffers are measured on a

52

scale of time instead of physical count. The entire time from material release to the start of

operation at the drum is considered as the buffer.9

5.2. The Buffer

Goldratt suggests that the time buffers must be established by applying a simple rule of

thumb, without getting into data collection and complex calculations.

𝑇𝑖𝑚𝑒 𝐵𝑢𝑓𝑓𝑒𝑟 = 𝐿𝑒𝑎𝑑 𝑡𝑖𝑚𝑒 𝑓𝑟𝑜𝑚 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙 𝑟𝑒𝑙𝑒𝑎𝑠𝑒 𝑡𝑜 𝑑𝑟𝑢𝑚2

To arrive at this time buffer, the lead time from release of grey material to beginning of

sewing was required to be calculated. In general two kinds of processing is required by the grey

fabric – Printing and Dyeing. This time was calculated by tracking 9 running orders from grey

issue to dispatch. The tracking of these orders is presented in appendix G.1 to G.9. However, all

of these orders required dyed fabric. Orders requiring printed fabric were scheduled for sewing at

a time beyond the duration of this phase of the research. Thus, only historical lead times for

printing could be collected. The lead time from receipt of material to start of sewing was

determined from the 9 orders which were actually tracked. This time was added to the lead time

for printing to arrive at the time buffer for orders requiring printed fabric. The orders were

tracked by “Sheet Numbers” – the plant’s term for uniquely identifying each product.

The lead times and time buffers derived from them are described in Table 5.1 A and 5.1 B

below. These time buffers in front of the drum are called production buffers. Their purpose is to

protect the drum against variation in upstream processes. The production was tracked by

9 This concept has been explained by Schragenheim and Dettmer. See 21.A in the Review of Literature.

53

recording the daily output for each Sheet Number. Since sewing lines required up to six hours to

generate an output, the start of sewing is considered to be one day before the output is recorded.

Sheet No. Grey Issue Start

Receive Start

Receive End

Sewing Start Lead Time Lead Time

A B C D E F = C to E G = B to E

1664 A 22/2 8/3 18/3 17/3 10 24 1664 B 18/2 26/2 28/2 10/3 13 21 1664 C 18/2 26/2 28/2 15/3 18 26 1664 D 16/2 13/3 16/3 18/3 6 31 1664 E 10/2 20/2 22/3 7/3 16 26 1664 F 16/2 20/2 3/3 14/3 21 27 1660 A 20/3 22/3 22/3 5/4 15 17 1660 B 6/3 13/3 13/3 2/4 21 28 1660 C 10/3 27/3 27/3 6/4 11 28

Median Lead Time 15.5 ~ 15 26

Table 5.1 A - Lead time from Material Release to Sewing for Dyed Products

Sheet No. Grey Issue Start Receive Start Receive End Lead Time Lead Time

H I J K L = I to J M = Median of F + L

1545 A 21/1 14/2 3/3 25 40 1598 A 2/1 22/1 27/1 21 36 1598 B 26/12 17/1 17/1 23 38 1598 C 4/1 30/1 30/1 27 42 1598 D 6/1 19/1 23/1 14 29 1531 A 17/1 9/2 12/2 24 39 1531 B 23/1 3/2 6/2 12 27 1531 C 22/1 3/2 19/2 13 28

Median Lead Time 37

Table 5.1 B – Lead time from Material Release to Sewing for Printed Products

The production buffer was calculated by applying the rule of thumb to the above lead times.

The median lead times were considered for this purpose as they represent the most likely

54

situation. The buffers for dyed and printed products were calculated as 13 and 18.5 days

respectively. However, these times need not be strictly followed. If one strongly feels to increase

or decrease this time within reasonable limits, it should be done.

Since solid dyeing is outsourced to dyers within the city of the plant, 13 days seemed too

long. It was reduced to 10 days. Printing is carried out by suppliers in another district. Since

there is lower control over them, the buffer was increased from 18.5 to 20 days.

Thus, the production buffer size for dyed and printed products were determined to be

Product Type Production Buffer Size Dyed 10 Days

Printed 10 Days

Table 5.2 – Production Buffer Size

This production buffer protects the drum against variation in upstream processes. But another

kind of variation must also be considered, the variation within the drum itself. This variation is

protected by a shipping buffer, the time from the end of the drum to shipping. A similar process

to that followed for determining the production buffer can be used to calculate the shipping

buffer. In this case, the drum was at the end of the system. A one day shipping buffer should

have been sufficient but to add more safety, a two day shipping buffer was used. The drum and

buffers are shown in the figure below.

Dyed Printed Production Buffer Drum Shipping Buffer

Figure 5.1 – Drum and Buffer

55

5.3. The Rope

The output of the system is determined by the output of the constraint. Hence, releasing more

material than the constraint can use will only increase inventory without affecting the system.

The release of material should be choked. It must be linked to the schedule of the drum. The

figure below shows the effect of choking material release on due date performance.

Figure 5.2 - Real life example of the effect of choking the release on the due date performance Source: Goldratt, 2009

It clearly shows that choking material release by linking it to the drum schedule has

immediate positive impact on a plant’s due date performance.

56

5.4. Drum-Buffer-Rope Schedule

The above concepts were applied to execute three production orders comprising nine sheet

numbers. The plant approved the use of two sewing lines, thus two drums, to run these orders.

The details of these orders in presented in tables 5.3 A and 5.3 B below.

Style # Sheet # Description Quantity Size Ratio S M L XL

U-9881 1738 F Dyed 5 Tier Skirt 3200 800 1600 800 1738 G Dyed 5 Tier Skirt 3200 800 1600 800 1738 H Dyed 5 Tier Skirt 4800 1200 2400 1200

DM-10-32 1732 A M&M Printed 5 Tier Skirt 600 100 200 200 100 DM-10-41 1732 B M&M Printed 5 Tier Skirt 600 100 200 200 100 DM-10-31 1732 C M&M Printed 5 Tier Skirt 600 100 200 200 100 DM-10-37 1732 D M&M Printed 5 Tier Skirt 600 100 200 200 100

UU76771 1714 A Women’s Top /w Lace 504 84 168 168 84 1714 B Women’s Top /w Lace 432 72 144 144 72

Table 5.3 A – Details of orders executed on the Drum

Sheet # Due Date

1738 F 17 April, 2010 1738 G

1738 H 1732 A

22 April, 2010 1732 B 1732 C 1732 D 1714 A 25 April, 2010 1714 B

Table 5.3 B – Due dates of orders executed on the Drum

57

These due dates represent the shipping schedule. Subtracting the shipping buffer from this

shipping schedule would determine the end date of the order at the drum. To determine the start

date at the drum to create the drum schedule, the estimate of the lead time at the drum is

required. This may be achieved by in two ways –

1. Conducting time study to determine the work content of the garment

2. Using estimates provided by sewing & finishing line supervisors

Time estimate determined by time study was used for four sheets. For the remaining five

sheets, the estimates provided by the supervisors were used. An estimate of the learning curve

was also required. This learning curve was considered in the form of percentage of the estimated

hourly output as expected on a particular day from the start of production on a style. The hourly

output from sewing and learning curve estimates for each style is shown below. Each sewing line

consisted of 36 machines.

Sheet # SAM Learning Curve (%) Average Hourly Output I II III

U-9881 - 45% 80% 100% 48 DM-10-XX 32.5 45% 80% 100% 45 UU76771 - 45% 80% 100% 50

Table 5.4 – Estimating Work Content

Now, three essential data were available to create the schedule.

1. Shipping Schedule

2. Time Buffers

3. Work Content at Drum

58

With this information, the date of start at drum and material release can be determined. The

process is illustrated in the table below.

Ex-Factory Date A Date Shipping Buffer B Days Work Content at Drum C Days Start Date at Drum D Date Production Buffer E Days Material Release F Date

D = A – B – C and F = D – E For Example, if A = 17th April, B = 2 Days, C = 10 Days and D = 10 Days Thus,

D = 17th April – 12 Days = 3rd April and F = 3rd April – 10 Days = 22nd March

(While calculating, only working days are considered)

Figure 5.3 – Determining Drum Start and Material Release

The above stated method was used to determine the drum schedule of two drums. Estimates

of the work content were used to determine the due dates at the drum. For sake of control and

checking the validity of the drum, each was explicitly planned. One plan is shown in the table

below. Plans for each sheet are shown in appendices J.1 & J.2.

59

Average Hourly Output 44 Cumulative

Feed Batch Size 180 Day Output S M L XL S M L XL

1 280 60 120 70 30 60 120 70 30 2 350 55 86 136 73 115 206 206 103 3 350 48 120 120 60 163 326 326 163 4 350 43 86 86 43 206 412 412 206

Day Status at End of Day

Packed Ratio - 1:2:2:1

S M L XL S M L XL Total 1 60 120 70 30 30 60 60 30 180 2 85 146 146 73 73 146 146 73 438 3 60 120 120 60 60 120 120 60 360 4 43 86 86 43 43 86 86 43 258

Table 5.5 – Detail plan for Sheet No. 1732 A and 1732 B fed to Drum I consecutively

Such detailed planning at the drum allows for better estimates of the work duration at the

drum. Once these durations are calculated, the drum schedule must be prepared. The drum

schedules for both drums used for the application are given below. These drum schedules must

be strictly followed as any deviation in these drums directly impacts the system’s throughput.

The drum schedule is a simple list of work orders. The supervisor of a drum is made

responsible for making sure that each work order is started precisely as per the schedule. The

drum supervisor must ascertain the availability of cut parts, trims and accessories from upstream

processes. In case of any problem, the buffer manager is intimidated for resolution of the matter.

60

Sheet #

Date Drum I Drum II

27/3 1738 H N/A 28/3 Sunday 29/3 1738 H 1738 F 30/3 1738 H 1738 F 31/3 1738 H 1738 F 1/4 1738 H 1738 F 2/4 1738 H 1738 F 3/4 1738 H 1738 F 4/4 Sunday 5/4 1738 H 1738 F 6/4 1738 H 1738 F 7/4 1738 H 1738 F 8/4 1738 H 1738 F; 1738 G 9/4 1738 H 1738 G 10/4 1738 H 1738 G 11/4 Sunday 12/4 1738 H;1738 G 1738 G 13/4 1738 G 1738 G 14/4 1738 G; 1732 A 1738 G; 1732 C 15/4 1732 A 1732 C 16/4 1732 A; 1732 B 1732 C; 1732 D 17/4 1732 B 1732 D 18/4 Sunday 19/4 1732-B & 1714 A 1732 D 20/4 1714 A N/A 21/4 1714 A; 1714 B N/A 22/4 1714 B N/A

Table 5.6 – Drum Schedule

The material release schedule was created with respect to this drum schedule. This

synchronization between material release and the drum schedule is the most essential step of a

Theory of Constraints application. It subordinates all activities to the constraint. The material

release schedule is also called the gating schedule. It is shown in the table below.

61

Date Sheet # Upper Lining (Meters) (Meters)

16/3 1738 H 8100 3180 17/3 1738 F 5380 2150 22/3 1732 A 1125 22/3 1732 C 1125 24/3 1732 B 1125 24/3 1732 D 1125 27/3 1738 G 5380 2150 2/4 1732 A 400 2/4 1732 C 400 5/4 1732 B 400 5/4 1732 D 400 7/4 1714 A 490 125 8/4 1714 B 410 110

Table 5.7 – Material Release Schedule

5.5. Buffer Management

So far the concept of DBR has been discussed; however there is a second part of this act

which is equally important and imperative for successful implementation of DBR. This second

part is Buffer management; it is the control system that allows us to keep a running check on the

system’s effectiveness. The drum-buffer-rope model, once established, needs a monitoring

system to keep it in control which is achieved by buffer management. Buffer management

surfaces the important signals from the system warning us against the potential problems and

also acts as a litmus test to check whether too much and or too little protection is being given for

any order. Before understanding the role of buffer management, the role of buffers must me

clearly understood.

62

In a make-to-order environment, timeliness is of utmost importance. Buffers protect the

timeliness of the system by subordinating the raw material release and all other steps up to the

drum origin so that materials arrive in good time to be processed as planned and finished goods

can be shipped at the planned time. This is the role of buffers.

Buffer management begins by dividing the time buffers in to three equal/unequal zones.

Suppose the production buffer is of nine day; the first zone (green zone) would span for the first

three days, the second zone (yellow zone) would span the next three day and the third buffer (red

zone) would span the last three days. We expect most work to be completed in the first two

thirds and be waiting in front of the constraint for the last third of the buffer time. Thus in the

above mentioned example, one expects the work to take about 6 days of processing and waiting-

in-process, and then sitting in front of the drum for 3 days. If the materials are not ready for the

drum by the start of the third zone, the work order must be expedited to make sure that drum

schedule is not disturbed. The figure shown below illustrates zoning of the production buffer.

9 Day Production Buffer I II III

1 2 3 4 5 6 7 8 9 Green Zone Yellow Zone Red Zone

Figure 5.4 – Zoning of Buffers

In the case of implementation, the following zones were used

1. Production Buffer for Printed – 20 Days

a. Zone I - Day 1 to Day 8 - 8

b. Zone II - Day 9 to Day 14 - 6

c. Zone III - Day 15 to Day 20 - 6

63

2. Production Buffer for Dyed – 10 Days

a. Zone I - Day 1 to Day 4 - 4

b. Zone II - Day 5 to Day 7 - 3

c. Zone III - Day 8 to Day 10 - 3

Buffer management can be used for local control in order to avoid deviation from the drum

schedule or global feedbacks to address any buffer related issues for effective implementation of

drum-buffer-rope.

5.5.1 Local Control – Buffer status

Buffer status tells the status of an order that has already been released into the system.

Schragenheim defines buffer status as

𝐵𝑢𝑓𝑓𝑒𝑟 𝑆𝑡𝑎𝑡𝑢𝑠 (%) = 𝐵𝑢𝑓𝑓𝑒𝑟 𝐷𝑢𝑟𝑎𝑡𝑖𝑜𝑛 − 𝑅𝑒𝑚𝑎𝑖𝑛𝑖𝑛𝑔 𝐷𝑢𝑟𝑎𝑡𝑖𝑜𝑛𝐵𝑢𝑓𝑓𝑒𝑟 𝐷𝑢𝑟𝑎𝑡𝑖𝑜𝑛 𝑥 100

In other words buffer status indicates how much part of the total buffer has been exhausted.

For example, the production buffer for printed products was taken as 20 days. On the 7th day the

buffer status would be or 35%. A buffer status chart which has all the orders released into

the system helps to know the orders which might deviate from the planned schedule. If the buffer

status of any order is above 70% it indicates that the order has entered the red zone of the buffer

and needs to be expedited in order to prevent due date violation. Thus a daily buffer status chart

for all the released orders would indicate which orders require management attention to avoid

any divergence from the schedule.

64

A similar chart was maintained for all the released orders. In certain cases, it helped in

insinuating the necessary actions to avoid deviation from schedule. The buffer status report is

presented in Appendix K.

5.5.2. Global Feedback - Buffer Hole

A buffer hole is the depth or the duration by which the red zone has been penetrated. It is a

measure of the system’s stability and suggests whether the current buffer duration is apt or not. If

most of the orders lie in the green zone it implies that the buffer is more and unnecessary excess

inventory is being put into the system. Similarly if most of the orders are in the red zone it

implies that the buffer is small and should be increased to avoid any deviation from the schedule.

Buffer holes for the orders run using the drum-buffer-rope model are shown in the figures

below.

Figure 5.5A – Buffer holes in production buffer for dyed products

0

0.5

1

1.5

2

2.5

Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Day 8 Day 9 Day 10

65

Figure 5.5B Buffer holes in production buffer for printed products

In case of dyed products the incidences of buffer holes were less. However, in case of printed

products, the incidences of buffer holes were very high and thus called for improvements.

5.5.3. Global Feedback –Reason code analysis

The data obtained from buffer management can be used to direct improvements. An analysis

of all the orders gives a trend of receiving various orders in various buffer zones. The cause for

occurrence of red zone and frequency for each cause can be recorded. Necessary actions can then

be taken so that these causes are not repeated in the future or at least their frequency is reduced.

The following figure shows the different zones in which the production buffers for the work

orders were exhausted. It is followed by a table listing the causes for penetration of the red zone

with their frequency.

0

0.5

1

1.5

2

2.5

Day

1

Day

2

Day

3

Day

4

Day

5

Day

6

Day

7

Day

8

Day

9

Day

10

Day

11

Day

12

Day

13

Day

14

Day

15

Day

16

Day

17

Day

18

Day

19

Day

20

66

Figure 5.6 – Buffer Exhaustion

Reason Code Analysis (Red Zone ) Reason Frequency

Late arrival of Print/Dye fabric 6 Cutting 1 Total 7 Recommended Action Increase the buffer duration for printed materials.

Table 5.8 – Reason Code Analysis

5.5.4 Local Measurements

Apart from local controls and global feedbacks, buffer management is also helpful in

measuring two important aspects of a system - Throughput & Inventory. Whenever an order is

late and needs to be measured there is always confusion whether it should be measured in terms

of late days or sales value. Measuring in terms of just one criterion might result in under

estimation of the magnitude of a large order late by just 1 day or a small order late by several

Green Yellow Red0

1

2

3

4

5

6

7

8

67

days but of a low sales value. Buffer management addresses this old problem by taking a product

of the two factors. It is called throughput dollar days.

Goldratt suggests that in order to avoid late deliveries, the lateness should be tied to buffer

holes. Whenever a task does not arrive at its buffer-origin even though enough time has elapsed

since its release, it is likely to cause due date variation. Thus, we might start to count the days

from the point in time when the task penetrated into the red zone, rather than from the order

due-date. This delay is called Lateness.

𝐿𝑎𝑡𝑒𝑛𝑒𝑠𝑠 = 𝐴𝑐𝑡𝑢𝑎𝑙 𝐷𝑢𝑟𝑎𝑡𝑖𝑜𝑛 − 𝐵𝑢𝑓𝑓𝑒𝑟 𝐿𝑒𝑛𝑔𝑡ℎ − 𝐿𝑎𝑠𝑡 𝑍𝑜𝑛𝑒 𝐿𝑒𝑛𝑔𝑡ℎ

Using buffer management this way provides the probable location of the problem and its

frequency;; however from the system’s point of view it is more plausible to have some measure

of severity. More the throughput is at stake, and more the days are late; more severe is the

problem. Stein advocates that using this measure of severity in buffer hole Pareto analysis gives

a more clear and reliable picture of the system.

𝑆𝑒𝑣𝑒𝑟𝑖𝑡𝑦 = 𝑇ℎ𝑟𝑜𝑢𝑔ℎ𝑝𝑢𝑡 𝑥 𝐿𝑎𝑡𝑒𝑛𝑒𝑠𝑠

Sheet No. Throughput Lateness Severity 1732 A 88800 3 266400

1732 B 88800 4 355200 1738 C 88800 2 177600 1738 D 88800 2 177600 1738 F 280160 2 560320 1738 H 420240 3 1260720 1738 B 34344 1 34344

Table 5.9 – Severity

68

A daily location wise severity chart assigns the resulting measure to the unit where the

process is stuck and might cause a due date variation. Sometimes it might give a false picture as

that department might not be responsible for the lateness - but the result to the system is the

ultimate goal. The centre that inherits the problem will, in effect, expedite the resource with a

severity tied to it and try to move it out of the department as soon as possible. The quality control

department however should make it sure that the work done is not sloppy in this case.

Such daily location wise measure of severity was done for the implemented orders to make

sure that an order with severity tied to it has a higher priority at the non-constraint resources. The

table below gives the magnitude of severity on a particular day and the department to which it

belongs.

Department 24-Mar 25-Mar 07-Apr 08-Apr 09-Apr 10-Apr 12-Apr

Printing/Dying Receive 420240 88800 177600 88800

Print Checking 177600 266400

Cutting 1120640 88800 88800

Smoking

Table 5.10 – Daily Severity Chart

69

06. Results

70

6.1. Planned v/s Actual

The planned orders were fed into the system and the actual performance was measured to

gauge the effectiveness of scheduling. When the orders were planned daily estimates of the

drum’s output, total number of pieces packed, status at the end of day and number of unpacked

pieces were estimated. These factors were then compared with actual data collected from the

implementation. One such comparison is shown in the table below.

Date 15/4 Status at Drum Output S M L XL Total

Sewing Expected 60 120 70 30 280 Actual 60 120 80 30 290

Available for Pack at End of Day Expected 60 120 70 30 280 Actual 60 120 80 30 290

Packing Expected 30 60 60 30 180 Actual 30 60 60 30 180

Un-Packed (Waiting for Size Ratio) Expected 30 60 10 0 100 Actual 30 60 20 0 110

Table 6.1 – Planned v/s Actual at Drum 1 on 15th April

In most cases, the actual output did not exactly match the planned output but most of them

were completed in the planned drum duration. The daily packed output as planned and as it

occurred in reality were compared for both the drums. It revealed that although there were

deviations within an order’s schedule, it largely evened out to be completed on time. It shows

that keeping the bottleneck in the drum within sewing allows greater control and better accuracy

of planning.

71

DRUM 1 Date Sheet No. Planned Actual Cumulative

Planned Actual Deviation 27/3 1738 H 40 0 40 0 100.0 29/3 1738 H 360 400 400 400 0.0 30/3 1738 H 400 400 800 800 0.0 31/3 1738 H 400 360 1200 1160 3.3 01/4 1738 H 400 360 1600 1520 5.0 02/4 1738 H 320 280 1920 1800 6.3 03/4 1738 H 320 400 2240 2200 1.8 05/4 1738 H 360 400 2600 2600 0.0 06/4 1738 H 400 400 3000 3000 0.0 07/4 1738 H 400 400 3400 3400 0.0 08/4 1738 H 400 400 3800 3800 0.0 09/4 1738 H 400 400 4200 4200 0.0 10/4 1738 H 400 400 4600 4600 0.0 12/4 1738 H; 1738 G 400 400 5000 5000 0.0 13/4 1738 G 400 400 5400 5400 0.0 14/4 1738 G; 1732 A 520 520 5920 5920 0.0 15/4 1732 A 180 180 6100 6100 0.0 16/4 1732 A; 1732 B 438 438 6538 6538 0.0 17/4 1732 B 360 360 6898 6898 0.0 19/4 1732 B; 1714 A 258 258 7156 7156 0.0 20/4 1714 A 180 0 7336 7156 2.5 21/4 1714 A 342 120 7678 7276 5.2 22/4 1714 A; 1714 B 444 330 8122 7606 6.4 23/4 1714 B 0 516 8122 8122 0.0

Table 6.2 – Planned vs Actual comparison for packed output at Drum 1

72

DRUM 2 Date Sheet No. Planned Actual Cumulative

Planned Actual Deviation 29/3 1738 F 40 0 40 0 100.0 30/3 1738 F 360 400 400 400 0.0 31/3 1738 F 400 400 800 800 0.0 01/4 1738 F 400 400 1200 1200 0.0 02/4 1738 F 400 360 1600 1560 2.5 03/4 1738 F 320 440 1920 2000 4.2 05/4 1738 F 320 400 2240 2400 7.1 06/4 1738 F 360 400 2600 2800 7.7 07/4 1738 F 400 400 3000 3200 6.7 08/4 1738 F; 1738 G 400 400 3400 3600 5.9 09/4 1738 G 400 400 3800 4000 5.3 10/4 1738 G 400 400 4200 4400 4.8 12/4 1738 G 400 400 4600 4800 4.3 13/4 1738 G 400 560 5000 5360 7.2 14/4 1738 G; 1732 C 520 160 5520 5520 0.0 15/4 1732 C 180 360 5700 5880 3.2 16/4 1732 C; 1732 D 438 438 6138 6318 2.9 17/4 1732 D 360 438 6498 6756 4.0 19/4 1732 D 258 0 6756 6756 0.0

Table 6.3 – Planned vs Actual comparison for packed output at Drum 2

6.2. The Drum-Buffer-Rope Schedule

The orders which were run on the developed scheduling model were tracked to record their

performance against the planning. Their progress is presented in a calendar form below. The

chart shows the progress of each sheet number through the various processes along which it was

routed.

73

Date March, 2010 April, 2010

16 17 18 19 20 22 23 24 25 26 27 29 30 31 01 02 03 05 06 07 08 09 10 12 13 14 15 16 17 19 20 21 22 23 24 25

1738 F

1738 G

1738 H

1732 A

1732 B

1732 C

1732 D

1714 A

1714 B

Table 6.4 – Progress of Order scheduled by Drum-Buffer-Rope (Sundays are excluded)

74

6.3. New v/s Old

The orders executed using the drum-buffer-rope model is compared to orders that were run as

the on the plant’s conventional method. The comparison is shown in the table below.

Sheet No. Printed/Dyed Qty. Due date Actual

date Due date variation

On Time In Full

Lead time - Grey issue to Sewing

Start Conventional Planning

1664 A Dyed 3904 17/3 24/3 8 No 24 1664 B Dyed 3680 17/3 24/3 8 No 20 1664 C Dyed 4144 17/3 24/3 8 No 26 1664 D Dyed 3456 17/3 24/3 8 No 30 1664 E Dyed 4144 17/3 24/3 8 No 26 1664 F Dyed 3680 17/3 24/3 8 No 27 1660 A Dyed 1200 27/3 12/3 17 No 17 1660 B Dyed 1150 27/3 12/3 17 No 28 1660 C Dyed 1150 27/3 12/3 17 No 28

Drum-Buffer-Rope 1732 A Printed 600 22/4 22/4 0 Yes 20 1732 B Printed 600 22/4 22/4 0 Yes 20 1732 C Printed 600 22/4 22/4 0 Yes 20 1732 D Printed 600 22/4 22/4 0 Yes 20 1738 F Dyed 3200 17/4 17/4 0 Yes 10 1738 G Dyed 300 17/4 17/4 0 Yes 10 1738 H Dyed 4800 17/4 17/4 0 Yes 10 1714 A Dyed 504 25/4 25/4 0 Yes 10 1714 B Dyed 432 25/4 25/4 0 Yes 10

Table 6.5 – Performance Comparison

75

07. Limitations and Scope of Further Study

76

In this paper, the applicability of Theory of Constraints Drum-Buffer-Rope as a planning and

controlling system was illustrated. Although the concepts are generic in nature, their application

will be different in different environments. The case of implementation presented herein is only

one instance of this application. The implications however, can be generalized. Reducing

inventory will always lead to shortened lead times. Drum-Buffer-Rope provides a mechanism to

measure inventory on a scale of time and keep it to as low as the plant can afford it. In a make-

to-order environment, buffers protect the crucial timeliness of the system. It is evident from

results of the application; accurate due date performance is possible with shorter lead times and

less inventory.

7.1. Limitations

The major limitation is that the model developed herein cannot be, in fact, should not be

replicated in a different environment. Each environment must be analyzed to identify its

constraint and the drum-buffer-rope model should be applied accordingly. This case however

presents a case which is common to most made-to-order apparel manufacturing environments i.e.

the T plant structure where a host of products are made in different assembly lines. Any such

environment may apply the model described in this paper if its constraint lies in sewing.

Another limitation is that the instance of outsourced processes after sewing was not

considered. It was omitted as at the time of conduction the research since testing a model that

included outsourced processes such as garment wash or tie & dye was not possible due to the

limitations of the plant.

77

7.2. Scope for Further Study

The limitations described above present an opportunity for further research. The drum-

buffer-rope model can be designed to include those instances which require any extra processing

other than sewing, finishing and packing. In such a case, the continuity between sewing and

finishing would be broken and a different buffer management strategy would be required.

Theory of Constraints provides the power of focus. This enables improvement efforts to be

directed on those areas which would impact the bottom line most. By itself, theory of constraints

is a very high performing system. However, it can pull in elements of Lean, Six Sigma, and SPC

etc. in a highly focused and leveraged manner to improve itself. These improvement

philosophies should be applied to the constraint to increase its throughput thus impacting the

entire system.

A process of ongoing improvement based on theory of constraints might eventually lead to

the constraint shifting into the market. In such a case, market demand will determine the

system’s throughput. When this happens, an active internal bottleneck might not exist. Then, an

even simpler application known as Simplified Drum-Buffer-Rope can be applied.

Simplified Drum-Buffer-Rope is based on the same concepts as traditional Drum-Buffer-

Rope and is certainly in harmony with Theory of Constraints and the Five Focusing Steps. What

distinguishes it from traditional Drum-Buffer-Rope is its assumption of market demand as the

major system constraint, even when an internal capacity constraint temporarily emerges.10

10 Eli Schragenheim and H. William Dettmer

78

In mature apparel manufacturing environments, where stability has been achieved and the

system’s throughput is not dominated by an internal constraint, the Simplified Drum-Buffer-

Rope application can be implemented, thus simplifying the plant’s operating model.

79

08. Conclusion

80

The Theory of Constraints was developed in a made-to-order environment. There are several

formal Theory of Constraints applications where the detailed body of knowledge is rock-solid

and have been applied to hundreds or even thousands of different companies. The production

solution, which includes the planning and control technique known as Drum-Buffer-Rope can be

applied to any manufacturing business to generate the same outcomes. Hence, the production

solution is called an application.

This leads to the question that why has the theory of constraints not found popular

application in the apparel manufacturing industry. It may be argued that there is not much to gain

from it, but such an argument would be grossly inappropriate. As has been illustrated in this

paper, a very simple model applied in an unstable environment of high-mix/low-volume made-

to-order apparel manufacturing at an SME in Jaipur led to high due-date performance with

shortened lead times and reduced inventories. It was done without complex calculations or large

data collection efforts. This shows that drum-buffer-rope is a simple yet extremely powerful tool

to drive apparel manufacturers towards greater profits. Decreased lead times can provide

competitive edge to a company, and assuming there is no constraint in market demand, this could

lead to increased sales. The following co-relations also become true when lead times and

inventories are reduced –

Cost of inventory which includes costs like warehousing, handling, expedition and

working capital cost goes down.

Cost due to sales loss goes down.

Extra capacities are released, which reduces un-necessary cost of capital investment.

Ongoing improvement projects to improve bottlenecks increase throughput.

81

The apparel industry must eliminate its myopic view of focusing on local improvements.

Lean and Six Sigma are powerful tools but they must be applied keeping the impact on the

global system in mind. As has been implied in the paper, the first necessary condition for a

sustainable lean implementation is stability. This is exactly what Drum-Buffer-Rope provides. It

provides a schedule that works i.e. it remains valid and keeps the plant pumping out the right

products on time to meet delivery schedules despite inaccurate data, absenteeism, machine

breakdown, unreliable vendors, unexpected repair and rework etc.

The greatest advantage Theory of Constraints provides is the power or leverage. By focusing

on the constraint, the bottom line of the company can be directly affected. No other system, be it

Lean/JIT, Six Sigma or TQM acknowledges the existence of constraints. But that is never true.

Every system must have a constraint since if no constraints existed, the throughput of the system

would be infinite.

This simple acknowledgement of the existence of constraints has huge implications. It

challenges the very essence of the process of decision making my management. Traditional

management’s decisions are based on the older cost accounting model which apportions all costs

to products. Here lies a fundamental problem which is addressed comprehensively by the

financial application of Theory of Constraints known as Throughput Accounting. This basis of

cost allocation always prompts for actions which increase local efficiency. But once the

existence of constraints is acknowledges, the notion of local efficiency loses relevance. Theory

of Constraints prompts focus on global optima instead of local optimum. It has been applied to

hundreds of companies and documented evidence exist which showcase dramatic improvements.

82

Every system, however complex it might seem, is based on inherent simplicity. The more

complex a system is, the more it can gain by applying Theory of Constraints. Thus, apparel

manufacturers especially SMEs have much to gain from this body of knowledge.

8.1. Recommendations

Any company looking to implement the methods described in this paper must follow the

following steps.

1. Map the processes of the company.

Every plant is different. Hence, no two implementations will be the same. Thus,

all the processes from material release to the point of shipment must be mapped.

This will illustrate the inter-dependence between the various processes to reveal

the supply chain within the plan.

2. Identify the constraint

Since Drum-Buffer-Rope scheduling is designed on the constraint, the constraint

must first be identified. If the plant employs MRP/ERP systems, this can easily be

determined comparing the documented capacities of each process. However, since

most apparel SMEs do not employ such systems, they can simply identify the

constraint by an intuitive analysis of either of the three methods listed below –

- Finding the process where waiting time/inventory is highest

- The process which cause maximum disruption to downstream

processes

- Collect data on outputs of each process for a considerable period (a

month or above) to find the process with minimum productivity

83

3. Exploit the constraint

Since the constraint determines the throughput of the system, it must be exploited

to always be productive – doing what is supposed to be done. Each plant will have

a different exploitation strategy based on its operating environment. The best way

to exploit the constraint is to write a schedule for the constraint and make sure

that it is followed.

4. Subordinate everything to the constraint

This is done in order to protect the drum schedule from any variability. The drum-

buffer-rope model executes this subordination step by linking the material release

to the drum schedule. For applying the model, the production buffers must be

established and buffer management employed as has been described in chapter 5.

5. Elevate the constraint

Elevating the constraint is specific to each system. It should only be undertaken

once the constraint has been subjected to exploitation and subordination phases.

Lean/JIT, Six Sigma and TQM may be applied for elevation. Since now their

application is properly focused, their benefits would greatly impact the bottom line.

84

09. Bibliography

85

- Books -

Ford, 1922 Ford, Henry & Crowther, Samuel “Today and Tomorrow” Doubleday, Page & Co. (1926)

Ohno, 1988 Ohno, T. “Toyota Production System: Beyond Large-Scale Production.”

Productivity Press (1988)

Mabin & Balderstone, 2000

Goldratt, 1990

Johnson & Kaplan (1987)

Cox & Spencer,

1998

Umble & Srikanth, 1995

Senge, 1990

Mabin J. Victoria & Steven J. Balderstone “The world of the theory of constraints: a review of the international literature” CRC Press (2000)

Goldratt, E. M. “The haystack syndrome: sifting information out of the data ocean.” North River Press (1990)

Johnson, H. T., and Kaplan, R. S. “Relevance lost: the rise and fall of management accounting.” Harvard Business School Press (1987)

Cox, J. F. and Spencer, M. S. “The Constraints Management Handbook.” St. Lucie Press (1998)

Umble, M. and Srikanth, M. L. “Synchronous manufacturing: principles for world-class excellence” Spectrum Publishing (1995)

Senge, P. M. “The fifth discipline: the art & practice of the learning organization.” Random House (1990)

Goldratt, E.M,

1990

Goldratt & Cox, 1986

Goldratt,

1997

Stein, 1996

Schragenheim & Dettmer, 2000

Goldratt, E. M. “What is this thing called Theory of Constraints and how should it be implemented?” North River Press (1990)

Goldratt, E. M. and Cox, J. “The Goal – A Process of Ongoing Improvement” North River Press (1986)

Goldratt, E. M. “Critical chain.” The North River Press (1997)

Stein, R. E. “Re-engineering the manufacturing system: applying the theory of constraints (TOC).” Marcel Dekker (1996)

Schragenheim, E. and Dettmer, H. W. “Manufacturing at warp speed: optimizing supply chain financial performance.” The St. Lucie Press (2000)

86

- Articles -

Goldratt, 2009 Goldratt, E. M. “Standing on the Shoulders of Giants: Production Concepts versus Production Applications.” Gest. Prod. Vol. 16, No. 3 (2009)

Lee, Hwang,

Wang & Lee (2009)

Wheatley & Kellner-

Rogers, 1999

Scheinkopf, 1999

Umble & Umble, 1999

- Online Sources -

Woeppel, 2000

Youngman, 2005

Lee, J.H., Hwang, Y.J., Wang, M & Li, R.K. “Why Is High Due-Date Performance So Difficult to Achieve?—An Experimental Study” Production and Inventory Management Journal Vol. 45, No. 1 (2009)

s Wheatley, M. J. and Kellner-Rogers, M. “What Do We Measure and Why? Questions About The Uses of Measurement.” Journal for Strategic Performance Measurement (1999)

Scheinkopf, L. “Thinking for a change: putting the TOC thinking processes to use.” St Lucie Press/APICS series on constraint management (1999)

Umble, M. Michael and Umble, Elisabeth J. “Drum-Buffer-Rope for Lower Inventory” Industrial Management September (1999)

Woeppel, M. “Introduction to Drum-Buffer-Rope” http://www.pinnacle-strategies.com (2000)

Youngman, K.J. “A Guide to Implementing the Theory of Constraints (TOC)” http://www.dbrmfg.co.nz (2005)

87

Appendices

vi

Appendix A

vii

Appendix B

viii

Appendix C.1

ix

Appendix C.2

x

Appendix C.3

xi

Appendix C.4

xii

Appendix D

xiii

Appendix E

xiv

Appendix F

xv

Appendix G.1

xvi

Appendix G.2

xvii

Appendix G.3

xviii

Appendix G.4

xix

Appendix G.5

xx

Appendix G.6

xxi

Appendix G.7

xxii

Appendix G.8

xxiii

Appendix G.9

xxiv

Appendix H

xxv

Appendix I

xxvi

Appendix J.1

xxvii

Appendix J.2

xxviii

Appendix K

xxix

Annexures

xxx

Annexure 1

Training Needs identified for Managers and Supervisors my Method Apparel Consultancy in the NCR region depicting dismal realities.

Appendix A

SewingThead

CuttingFinishing Packing Sewing

Thead Cutting

Finishing Packing

8/3 3902 5412 5501 3810 - - - -9/3 3187 5903 5016 4565 - - - -

10/3 2379 4433 4165 3380 3156 5249 4894 3918 Sewing11/3 4335 3249 1440 1260 3300 4528 3540 3068 Packing12/3 6788 3682 3304 1300 4500 3788 2970 1980 Packing13/3 7937 4364 3418 2506 6353 3765 2721 1689 Packing15/3 4664 3887 3218 2000 6463 3978 3313 1935 Packing16/3 3795 4147 6057 4910 5465 4133 4231 3139 Packing17/3 3809 2839 5023 1407 4089 3625 4766 2772 Packing18/3 4552 3445 6454 8552 4052 3477 5845 4956 Thread Cutting19/3 5748 5949 4388 4574 4703 4078 5288 4844 Thread Cutting20/3 7269 4635 5207 1610 5856 4676 5350 4912 Thread Cutting22/3 5063 3680 4456 8533 6027 4755 4684 4906 Finishing23/3 5967 3480 5072 8884 6100 3932 4912 6342 Thread Cutting24/3 3371 4661 1810 1740 4801 3940 3779 6386 Finishing25/3 5934 4142 5322 3940 5091 4094 4068 4855 Finishing26/3 4309 2452 6309 3790 4538 3752 4480 3157 Packing27/3 4139 3750 2777 2810 4794 3448 4803 3513 Thread Cutting29/3 3732 3521 3055 5672 4060 3241 4047 4091 Thread Cutting30/3 3445 2111 3261 1260 3772 3127 3031 3247 Finishing31/3 4410 3379 5376 2403 3863 3004 3897 3112 Thread Cutting1/4 2221 3292 4666 1800 3359 2927 4434 1821 Packing2/4 2763 3156 4897 8580 3131 3276 4980 4261 Sewing3/4 6102 3410 1512 1460 3695 3286 3692 3947 Thread Cutting5/4 2859 3918 3671 6506 3908 3495 3360 5515 Finishing6/4 2019 4806 4790 2210 3660 4045 3324 3392 Finishing7/4 3577 4376 3270 8290 2818 4367 3910 5669 Sewing

DateOutput of Process 3 Day Moving Average

Bottleneck

0123456789

Sewing Thread Cutting Finishing Packing

Bottleneck Frequency

vi

Appendix B

Fabric for Body - - - - - Logical FlowRaw Material (Grey Fabric)

Cutting

Sewing

Thread Cutting

Finishing

Packing

Plant Structure - MA'AM Arts, Jaipur

Solid Dye

Print X

Print Y

_____ Physical Flow

1 Single Print

V/A/T AnalysisThe above structure illustrates the flow of products and processes. In this case, the plant has the characteristics of a T-Plant but the T structure is not clearly visible.

2

3

Mix & Match Prints

Solid Dye

Product Types

Operation Fabric for Lining

vii

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xi

Product Types V/A/T Analysis

1 Single Print The above structure illustrates the proposed logical flow of products and processes. Thread cutting as a separate process has been eliminated and a clear T structure is revealed.

2 Mix & Match Prints

3 Solid Dye

Operation Fabric for Lining - -

Solid Dye

Proposed Logical Plant Structure

Raw Material (Grey Fabric)

Fabric for Body Constraint Operation

Sewing

Print Y

Print X

Cutting

Drum 1 Drum 2 Drum 3

Packing

Finishing

Appendix D

xii

Appendix E

SMV

Attaching 9 panels of 8 th Tier 154.64 139.43 135.55 138.65 142.44 141.11 139.44 19.52 158.96 4.31Attaching 5 panels of 7 th Tier 84.01 77.41 71.81 81.51 75.17 78.07 76.79 10.75 87.54 3.53Attaching 3 panels of 6 th Tier 48.70 46.75 51.51 38.25 45.29 46.93 45.75 6.40 52.15 3.45Attaching 3 panels of 5 th Tier 51.03 38.91 47.94 54.58 47.45 47.45 47.27 6.62 53.89 2.85Attaching 2 panels of 4 th Tier 31.76 26.89 32.62 28.44 29.81 28.64 29.28 4.10 33.38 1.62Attaching 2 panels of 3 rd Tier 34.28 39.90 24.14 30.55 31.88 28.53 31.00 4.34 35.34 1.06Attaching 2 panels of 2 nd Tier 26.43 22.68 25.97 23.59 25.27 24.87 24.48 3.43 27.90 1.47Attaching 2 panels of 1 st Tier 21.43 20.48 18.96 19.29 19.55 19.52 19.56 2.74 22.30 0.87Gathering of 8 th Tier 137.32 118.04 121.18 148.53 128.89 129.14 129.15 18.08 147.24 9.92Gathering of 7 th Tier 69.19 59.18 71.38 57.43 66.77 78.52 66.66 9.33 75.99 6.79Gathering of 6 th Tier 73.42 80.68 71.78 46.68 70.20 77.52 69.37 9.71 79.08 5.66Gathering of 5 th Tier 53.43 47.29 46.68 50.69 50.62 50.84 49.23 6.89 56.12 2.69Gathering of 4 th Tier 51.68 50.05 51.36 41.10 48.05 50.86 48.28 6.76 55.04 3.37Gathering of 3 rd Tier 32.91 27.58 32.32 33.59 30.31 32.32 31.23 4.37 35.60 2.69Attachment of 8 th and 7 th Tier 426.88 382.67 370.27 389.27 374.46 377.68 378.87 53.04 431.91 5.03Attachment of 7 th and 6 th Tier 270.36 239.04 230.84 248.75 249.02 233.15 240.16 33.62 273.78 3.42Attachment of 6 th and 5 th Tier 278.92 223.58 212.54 353.35 249.56 216.52 251.11 35.16 286.26 7.35Attachment of 1 st and 2 nd Tier 77.05 69.68 69.35 67.10 67.59 68.01 68.35 9.57 77.91 0.86Attachment of 3 rd and 4 th Tier 97.66 106.24 86.20 85.48 85.67 86.26 89.97 12.60 102.57 4.90Attachment of 2 nd and 3 rd Tier 97.87 80.34 105.21 80.34 86.71 81.89 86.90 12.17 99.06 1.20Attachment of 2 nd and 3 rd Tier 166.13 176.23 160.48 131.62 151.56 120.85 148.15 20.74 168.89 2.75Lining attach 40.03 34.69 61.36 24.91 40.73 27.81 37.90 5.31 43.20 3.18Turn and top stitch of lining 103.92 83.95 93.69 101.29 99.36 105.30 96.72 13.54 110.26 6.34Lining attached to body 77.57 91.02 63.03 61.35 76.89 64.67 71.39 9.99 81.39 3.82Kaccha stitch at sides of waistband 23.10 22.64 16.07 23.60 21.69 22.92 21.38 2.99 24.38 1.27Close belt 55.78 57.66 44.62 53.12 53.83 50.70 51.99 7.28 59.26 3.48Attach belt to waist and hanger loop 93.77 98.41 87.93 78.00 86.36 76.52 85.44 11.96 97.41 3.64Close elastic band 8.71 7.96 8.25 7.98 8.18 7.47 7.97 1.12 9.08 0.37Attach elastic to the body 262.52 263.52 216.17 211.14 230.28 266.16 237.45 33.24 270.70 8.18Top secure stitch on elastic 48.34 41.07 52.62 42.13 42.41 39.49 43.54 6.10 49.64 1.30Label attach ( 2 labels at waist) 60.19 64.08 55.38 48.31 57.02 60.58 57.07 7.99 65.06 4.87Washcare label attach 37.68 39.37 31.55 33.39 36.03 38.29 35.73 5.00 40.73 3.05Bottom hem of lining 99.16 118.55 62.07 78.35 87.86 120.95 93.56 13.10 106.65 7.49

SAM 53.26 55.31 2.05

V

Allowance

@ 14%SMV

Increase in

Time

Readings (Thread Cut by Operators)Operation Avg. of 3 Readings x

Allowance @ 14%I II III IV

xiii

Appendix F

60 * 36 60 * 36

53.26 55.31

Thread ThreadCutting Cutting

800 40041 39

No. Rate (Rs.) Cost/Hour No. Rate (Rs.) Cost/Hour36 160 720.00 36 160 720.004 105 52.50 4 105 52.501 250 31.25 1 250 31.25

1/3 650 27.08 1/3 650 27.081 175 21.88 1 175 21.88

1/3 650 27.08 1/3 650 27.081/3 175 7.29 1/3 175 7.291/3 175 7.29

2 105 26.25

920.62 887.08

Net Profit (Throughput - Operating Expense)

102646 123832

Eliminating the Thread Cutting department by incorporating thread cutting at source by operators is compared to having a separate thread cutting department. They are compared on Lead Time and Costs based on Activity Based Costing and Throughput Accounting for a hypothetical order.

Throughput (Sales-Variable Costs) 199000.00 200000

300000 300000

Total Operating Expense 96354.50 76167.78

Days required 5.55 4.46

Operating Expense/Day 17364.99 17096.65

Net Profit 102646 123832

Hours to make 1000 Units

Comparing Lead Time based on Little's Law

Activity Based Costing

Cost Comparison Based on Throughput Accounting44.39 35.64

Floor Clerk

Thread Cutting Clerk

Thread Cutting Helper

Cost for 1000 Units 197354.50 176167.78Sales @ Rs. 300/Unit

Cost/Unit 197.35 176.17

10000 10000

Overhead/Minute 20.83 20.83

Cost/Minute 36.18 35.62

Minutes Produced 2663.41 2138.46

Labour Expense/Minute

Factory Overheads/Day

Cost/Unit14.78

0Thread Cutting Cost

Cost Component Cost/Unit15.34

Thread Cutting at SourceSeparate Thread Cutting DepartmentMeasurement

Throughput Rate (Per Hour Output)

= 41 = 39

800

Sewing Total

Manufacturing Lead Time(Inventory/Throughput Rate)

=

Inventory (Average WIP in Thread Cutting Department + Inventory in Sewing Line) 400 400

Sewing Total

Nil 400 400

Direct Material Cost 100.00 100.00

1020 =

Labour ExpenseOperators

Helpers

Line Master

Cost Comparison

1

Floor Incharge

QC @ End Line Inspection

Floor QC

Total Labour Expense/Hour

xiv

Appendix G.1

Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

Body22-Feb 2980 8-Mar 149 13-Mar 3565 15-Mar 3944 16-Mar 2630 18-Mar 2862 20-Mar 2990 22-Mar 1200

10-Mar 275917-Mar 1090 19-Mar 1088 22-Mar 920 23-Mar 2400

Lining 18-Mar 1015 18-Mar 394422-Feb 690 11-Mar 657 24-Mar 304

Net23-Feb 1035.3 18-Mar 1015

Packing

28-Jan

17-Mar

Grey Issue to Printing/Dyeing (Mts)

Receive Printing (Mts) Print Checking (Mts) Cutting Sewing

4500144645 1664 A

3904

UU76786

Smocking

Black

Lining

Average

Thread Cutting Finishing

Ship Date

Lead Time

Late Days

Production Track

Style #

PO #

PO Date

Due Date

Sheet #

Qty

24-Mar

31 Days

7 Days

Fabric

Body 72 cm

17.5 cm

xv

Appendix G.2

Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

Body19-Feb 2810 26-Feb 923 6-Mar 4375 9-Mar 3720 10-Mar 3720 11-Mar 140 12-Mar 130 19-Mar 3680

28-Feb 1835Lining 12-Mar 870 13-Mar 870

19-Feb 680 26-Feb 66213-Mar 1480 15-Mar 970

Net18-Feb 980 26-Feb 955 15-Mar 1190 16-Mar 1700

Average Ship Date 24-Mar

PO # 4500144646 Sheet # 1664 B Body 72 cm

Style # UU76786 Due Date 17-Mar White Fabric

Lead Time 36 Days

PO Date 28-Jan Qty 3680 Lining 17.5 cm Late Days 7 Days

Production TrackGrey Issue to

Printing/Dyeing (Mts)Receive Printing (Mts) Print Checking (Mts) Cutting Sewing Thread Cutting Finishing PackingSmocking

xvi

Appendix G.3

Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

Body19-Feb 3180 28-Feb 3111 12-Mar 4570 13-Mar 4200 13-Mar 1750 16-Mar 1050 17-Mar 1070 20-Mar 424

Lining 14-Mar 2444 17-Mar 2400 18-Mar 870 22-Mar 372019-Feb 780 26-Feb 778

18-Mar 740 19-Mar 2200Net

18-Feb 1080 11-Mar 684

Average Ship Date 24-Mar

PO # 4500144647 Sheet # 1664 C Body 72 cm

Style # UU76786 Due Date 17-Mar Blue Fabric

Lead Time 34 Days

PO Date 28-Jan Qty 4144 Lining 17.5 cm Late Days 7 Days

Production TrackGrey Issue to

Printing/Dyeing (Mts)Receive Printing (Mts) Print Checking (Mts) Cutting Sewing Thread Cutting Finishing PackingSmocking

xvii

Appendix G.4

Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

Body17-Feb 2650 16-Mar 2580 13-Mar 894 18-Mar 3504 18-Mar 2628 19-Mar 873 22-Mar 2240 24-Mar 3328

Lining 19-Mar 876 20-Mar 2625 23-Mar 121017-Feb 640 16-Mar 625 17-Mar 3200

Net16-Feb 910 13-Mar 894

Average Ship Date 24-Mar

72 cm

Fabric

Lead Time 36 Days

17.5 cm Late Days 7 Days

Production TrackGrey Issue to

Printing/Dyeing (Mts)Receive Printing (Mts) Print Checking (Mts)

PO # 4500144649 Sheet # 1664 D Body

Style # UU76786 Due Date 17-Mar Lush lawn

PO Date 28-Jan Qty 3456 Lining

Cutting Sewing Thread Cutting Finishing PackingSmocking

xviii

Appendix G.5

Date Qty (Mtrs) Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

Body11-Feb 3220 20-Feb 3125 24-Feb 5051 26-Feb 3200 27-Feb 2685 8-Mar 120 9-Mar 120 18-Mar 3840

Lining 26-Feb 1000 28-Feb 1450 9-Mar 420 10-Mar 420 19-Mar 30410-Feb 785 20-Feb 768

10-Mar 470 11-Mar 440Net

10-Feb 1180 22-Feb 1158 11-Mar 880 12-Mar 880

12-Mar 910 13-Mar 910

13-Mar 1080 15-Mar 1077

15-Mar 300 16-Mar 300

Average Ship Date 24-Mar

PO # 4500144651 Sheet # 1664 E Body 72 cm

Style # UU76786 Due Date 17-Mar Top - Pink Nova Fabric

Lead Time 42 Days

PO Date 28-Jan Qty 4144 Lining 17.5 cm Late Days 7 Days

Production TrackGrey Issue to

Printing/Dyeing (Mts)Receive Printing (Mts) Print Checking (Mts) Cutting Sewing Thread Cutting Finishing PackingSmocking

xix

Appendix G.6

Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

Body16-Feb 2780 20-Feb 2698 9-Mar 4298 11-Mar 3720 12-Mar 3720 15-Mar 810 16-Mar 830 13-Mar 1580 20-Mar 1136

Lining 16-Mar 2160 18-Mar 900 15-Mar 1419 22-Mar 84817-Feb 680 20-Feb 662

17-Mar 730 19-Mar 750 16-Mar 1938 23-Mar 1640Net

17-Feb 960 3-Mar 938 22-Mar 1190 17-Mar 1966 24-Mar 56

18-Mar 1066

19-Mar 1748

20-Mar 2811

22-Mar 3417

23-Mar 2841

24-Mar 4380

Average Ship Date 24-Mar

PO # 4500144653 Sheet # 1664 F Body 72 cm

Style # UU76786 Due Date 17-Mar Daisy Fabric

Lead Time 37 Days

PO Date 28-Jan Qty 3680 Lining 17.5 cm Late Days 7 Days

Production TrackGrey Issue to

Printing/Dyeing (Mts)Receive Printing (Mts) Print Checking (Mts) Cutting Sewing Thread Cutting Finishing PackingSmocking

xx

Appendix G.7

C

Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

A20-Mar 550 22-Mar 532 27-Mar 2208 29-Mar 1220 6-Apr 213 7-Apr 330 12-Apr 1200

7-Apr 430 8-Apr 300B

20-Mar 580 22-Mar 558 8-Apr 420 10-Apr 580

9-Apr 147C

20-Mar 1150 22-Mar 1118

90 cm

Average Ship Date 12-Apr

42.5 cm

Fabric

Lead Time 24 Days

45 cm Late Days 17 Days

Production TrackGrey Issue to

Printing/Dyeing (Mts)Receive Printing (Mts) Print Checking (Mts)

PO # AT91007 Sheet # 1660 A A

12002-FebPO Date Qty

Style # AT91007-3 Due Date 27-Mar Solid Off White

B

Cutting Sewing Thread Cutting Finishing PackingSmocking

xxi

Appendix G.8

C

Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

A6-Mar 535 13-Mar 518 29-Mar 2144 31-Mar 1170 3-Apr 85 9-Apr 1158 12-Apr 1150

B 5-Apr 3906-Mar 560 13-Mar 542

6-Apr 400C

6-Mar 1120 13-Mar 1084 7-Apr 290

90 cm

Average Ship Date 12-Apr

42.5 cm

Fabric

Lead Time 38 Days

45 cm Late Days 17 Days

A

B

Grey Issue to Printing/Dyeing (Mts)

Receive Printing (Mts) Print Checking (Mts)

PO # AT91007 Sheet # 1660 B

PO Date 2-Feb Qty 1150

Production Track

Style # AT91007-3 Due Date 27-Mar Solid Beige

Cutting Sewing Thread Cutting Finishing PackingSmocking

xxii

Appendix G.9

C

Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty Date Qty

A11-Mar 535 27-Mar 514 29-Mar 2146 30-Mar 1170 7-Apr 70 9-Apr 460 9-Apr 580 12-Apr 1150

B 8-Apr 390 10-Apr 435 10-Apr 133011-Mar 560 27-Mar 544

9-Apr 328 12-Apr 265 12-Apr 1670C

10-Mar 1120 27-Mar 1088 10-Apr 378

Sewing Thread Cutting Finishing PackingGrey Issue to Printing/Dyeing (Mts)

Receive Printing (Mts) Print Checking (Mts) Cutting Smocking

90 cm

Average Ship Date 12-Apr

42.5 cm

Fabric

Lead Time 32 Days

45 cm Late Days 17 days

A

B

PO # AT91007 Sheet # 1660 C

PO Date 2-Feb Qty 1150

Production Track

Style # AT91007-3 Due Date 27-Mar Solid Moca Brown

xxiii

C/T Upper 6.39 sec. ,

Lining 1.69 sec

27,000 x 2 sec available

C/T Upper 36 sec. ,

Lining 11.8 sec

27,000 x 3 sec available

C/T 3208 sec

27,000 x 30 sec.

available

144 sec.

24 days

8.08 sec.

2 days

47.8 sec

3 days

3208 sec.

7 days

2

Grey Store

24 days

C/T 144 sec

27,000 x 2 sec.

available

2 days

2

Printed fabric checking

3 days

3

Cutting

30

Sewing

7 days

1

Thread Cutting

C/T 196 sec

27,000 sec. available

1 day

1

Pressing

¼ days

C/T 43 sec.

27,000 sec. available

1

Checking

¼ days

C/T 58 sec.

27,000 sec. available

5

Packing

C/T 153 sec.

27,000 x 5 sec. available

1day

43 sec.

¼ days

58 sec.

¼ days

153 sec.

1 day

196 sec

1day

Production lead time (from Grey issue)- 14.5 days

Processing lead time- 3857.88 sec.

Appendix H

xxiv

S M L XL S M L XL S M L XL S M L XL1738 H 1 160 50 100 10 50 100 10 50 100 10 10 20 10 40

" 2 300 100 110 90 150 210 100 140 190 90 90 180 90 360" 3 380 90 190 100 240 400 200 140 200 100 100 200 100 400" 4 380 80 200 100 320 600 300 120 200 100 100 200 100 400" 5 380 80 200 100 400 800 400 100 200 100 100 200 100 400" 6 380 100 200 80 500 1000 480 100 200 80 80 160 80 320" 7 380 100 200 80 600 1200 560 120 240 80 80 160 80 320" 8 380 100 190 90 700 1390 650 140 270 90 90 180 90 360" 9 380 100 180 100 800 1570 750 150 270 100 100 200 100 400" 10 400 100 200 100 900 1770 850 150 270 100 100 200 100 400" 11 400 100 200 100 1000 1970 950 150 270 100 100 200 100 400" 12 400 100 200 100 1100 2170 1050 150 270 100 100 200 100 400" 13 400 100 200 100 1200 2370 1150 150 270 100 100 200 100 400

1738 H; 1738 G 14 400 100 200 100 1300 2570 1250 150 270 100 100 200 100 4001738 G 15 400 100 200 100 1400 2770 1350 150 270 100 100 200 100 400

1738 G; 1732 A 16 400 80 190 130 1480 2960 1480 130 260 130 130 260 130 5201732 A 17 280 60 120 70 30 60 120 70 30 60 120 70 30 30 60 60 30 180

1732 A; 1732 B 18 350 55 86 136 73 115 206 206 103 85 146 146 73 73 146 146 73 4381732 B 19 350 48 120 120 60 163 326 326 163 60 120 120 60 60 120 120 60 360

1732 B; 1714 A 20 350 43 86 86 43 206 412 412 206 43 86 86 43 43 86 86 43 2581714 A 21 200 50 60 60 30 50 60 60 30 50 60 60 30 30 60 60 30 180

1714 A; 1714 B 22 320 37 114 114 57 87 174 174 87 57 114 114 57 57 114 114 57 3421714 B 23 400 74 148 148 74 161 322 322 161 74 148 148 74 74 148 148 74 444

Detailed Schedule for Drum I

Annexure J.1

xxvi

TotalSheet #Size Wise Output Cumulative Status at End of Day Packed

Day Output

S M L XL S M L XL S M L XL S M L XL1738 F 1 160 50 100 10 50 100 10 50 100 10 10 20 10 401738 F 2 300 100 110 90 150 210 100 140 190 90 90 180 90 3601738 F 3 380 90 190 100 240 400 200 140 200 100 100 200 100 4001738 F 4 380 80 200 100 320 600 300 120 200 100 100 200 100 4001738 F 5 380 80 200 100 400 800 400 100 200 100 100 200 100 4001738 F 6 380 100 200 80 500 1000 480 100 200 80 80 160 80 3201738 F 7 380 100 200 80 600 1200 560 120 240 80 80 160 80 3201738 F 8 380 100 190 90 700 1390 650 140 270 90 90 180 90 3601738 F 9 380 100 180 100 800 1570 750 150 270 100 100 200 100 400

1738 F; 1738 G 10 380 100 200 100 900 1770 850 150 270 100 100 200 100 4001738 G 11 380 100 200 100 1000 1970 950 150 270 100 100 200 100 4001738 G 12 400 100 200 100 1100 2170 1050 150 270 100 100 200 100 4001738 G 13 400 100 200 100 1200 2370 1150 150 270 100 100 200 100 4001738 G 14 400 100 200 100 1300 2570 1250 150 270 100 100 200 100 400

1738 G; 1732 C 15 400 80 190 130 1380 2760 1380 130 260 130 130 260 130 5201732 C 16 280 60 120 70 30 60 120 70 30 60 120 70 30 30 60 60 30 180

1732 C; 1732 D 17 350 55 86 136 73 115 206 206 103 85 146 146 73 73 146 146 73 4381732 D 18 350 48 120 120 60 163 326 326 163 60 120 120 60 60 120 120 60 3601732 D 19 350 43 86 86 43 206 412 412 206 43 86 86 43 43 86 86 43 258

xxvii

Sheet # Day OutputSize Wise Output Cumulative Status at End of Day Packed

Total

Detail Schedule for Drum II

Annexure J.2

Annexure K

Date 22/3 23/3 24/3 25/3 26/3 27/3 29/3 30/3 31/3 1/4 2/4 3/4 5/4 6/4 7/4 8/4 9/4 10/4 12/4 13/4 14/4 15/4

1732-A 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Buffer Status 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85

1732-B 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Buffer Status 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90

1732-C 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Buffer Status 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

1732-D 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Buffer Status 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Date 16/3 17/3 18/3 19/3 20/3 22/3 23/3 24/3 25/3 26/3 27/3 29/3 30/3 31/3 1/4 2/4 3/4 5/4 6/4 7/4

Sheet 1738-H 1 2 3 4 5 6 7 8 9 10Buffer Status 10 20 30 40 50 60 70 80 90 100

Sheet 1738-G 1 2 3 4 5 6 7 8 9 10Buffer Status 10 20 30 40 50 60 70

Sheet 1738-F 1 2 3 4 5 6 7 8 9 10Buffer Status 10 20 30 40 50 60 70 80 90

Date 7/4 8/4 9/4 10/4 12/4 13/4 14/4 15/4 16/4 17/4 19/4 20/4

1714-A 1 2 3 4 5 6 7 8 9 10Buffer Status 10 20 30 40 50 60 70

1714-B 1 2 3 4 5 6 7 8 9 10Buffer Status 10 20 30 40 50 60 70 80

Lateness = 3 Days

Lateness = 0 Days

Lateness 2 Days

Lateness = 0 Days

Lateness = 1 Day

Lateness = 4 Days

Lateness = 2 Days

Lateness = 3 Days

Lateness = 2 Days

xxviii

xxx

Annexure 1

Training Needs identified for Managers and Supervisors my Method Apparel Consultancy in the NCR region depicting dismal realities.