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International Journal of Engineering and Technology Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1056
Productivity Improvement by using Six-Sigma
Md. Enamul Kabir, S. M. Mahbubul Islam Boby, Mostafa LutfiDepartment of Industrial Engineering and Management,
Khulna University of Engineering & Technology, Khulna- 9203, Bangladesh
ABSTRACT
Globalization, advanced technology, and increased sophisticated customer demands change the way of conducting business. Old
business models no longer work in new economy. Defects rate of product plays an important role for the improvement of yield and
financial conditions of any company. The objectives of this paper are to study and evaluate processes of the case organization, to find
out current sigma level and finally to improve existing sigma level through productivity improvement. According to the objectives,
current sigma level has been calculated and given suggestions for improvement. This has been done by using six-sigma DMAIC
cycle. Especially in improve phase of DMAIC cycle, different improvement tools are used like 5s, supermarket and line balancing
etc. By using these it has been possible to improve productivity by reducing defect rate. This research work has been carried out in a
fan manufacturing company to show how to improve its productivity and quality by using Six-sigma. This paper related to work is
not only applied to fan manufacturing company but also in any other types of organizations. By implementing Six-sigma a perfect
synchronization among cost, quality, production time and control time will be observed.
Keywords: improvement, sigma level, DMAIC cycle, 5S, supermarket, line balancing.
1. INTRODUCTION
Six- Sigma is a statistical measurement of only 3.4 defects
per million. Six-Sigma is a management philosophy focused
on eliminating mistakes, waste and rework. It establishes a
measurable status to achieve and embodies a strategic
problem-solving method to increase customer. Satisfaction
and dramatically reduce cost and increase profits. Six-Sigma
gives discipline, structure, and a foundation for solid decision
making based on simple statistics. The real power of Six
Sigma is simple because it combines people power with
process power. The Six Sigma is a financial improvement
strategy for an organization and now a day it is being used in
many industries. Basically it is a quality improving process of
final product by reducing the defects; minimize the variation
and improve capability in the manufacturing process. The
objective of Six Sigma is to increase the profit margin,
improve financial condition through minimizing the defects
rate of product. It increases the customer satisfaction,
retention and produces the best class product from the best
process performance.
If an organization is focused on customer satisfaction, then
Six Sigma will offer a method and some tools for the
identification and improvement of both internal and external
process problems to better meet customer needs by
identifying the variations in organization’s processes that
might influence the customer’s point of view, negatively.
The purposes of this paper are
To study and evaluate processes at a fan
manufacturing company
To calculate the current sigma level of that
manufacturing company
To develop in order to get competitive advantage in
the long run
To give suggestions for improvements by using
Six-Sigma DMAIC process improvement methods.
2. LITERATURE REVIEW
The literature review will give a basic idea about the
evolution of six-sigma, what it is about and its methodology.
Some case studies to highlight its importance are also
discussed in this literature review. Case studies will brief
about six-sigma and how it has helped in productivity
improvement.
2.1 Six-Sigma Evolution
Though Fredrick Taylor, Walter Shewhart and Henry Ford
played a great role in the evolution of six-sigma in the early
twentieth century, it is Bill Smith, Vice President of Motorola
Corporation, who is considered as the Father of Six-sigma.
Fredrick Taylor came up with the methodology of breaking
systems into subsystems in order to increase the efficiency of
manufacturing process. Henry Ford followed his four
principles, namely continuous flow, interchangeable parts,
division of labor and reduction of wasted effort, in order to
end up in an affordable priced automobile. The development
of control charts by Walter Shewhart laid the base for
statistical methods to measure the variability and quality of
various processes.
Later during the 1950s, the Japanese Manufacturing sector
revolutionized their quality and competitiveness in the world
based on the works of Dr. W. Edwards Deming, Dr. Armand
Feigenbaum, and Dr. Joseph M Juran. Dr. W. Edwards
Deming developed the improvement cycle of ‘Plan-Do-
Check-Act’, better known as the PDCA cycle. Dr. Joseph M
Juran gave to the world his ‘Quality Trilogy’ and it was Dr.
Armand Feigenbaum who initiated the concepts of ‘Total
International Journal of Engineering and Technology (IJET) – Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1057
Quality Control’ (TQC). Between 1960 and 1980, the
Japanese understood that everyone in an organization is
important to maintain quality and so training programs were
conducted for almost all employees not considering the
department they belong to. Any organization that is
dynamically working to build the theme of six-sigma and to
put into practice, the concepts of six-sigma, in its daily
management activities, with noteworthy improvements in the
process performance and customer satisfaction is considered
as a six –sigma organization [3].
2.2 Related Works
M. Soković et al. undertook projects to identify areas in the
process where extra expenses exist, identify the biggest
impact on production expenses, introduce appropriate
measurement system, improve process and reduce expenses
on production times, and implement improvements [4].
Gustav Nyren represented the variables influencing the
chosen characteristics variable and then optimized the process
in a robust and repeatable way [5].John Racine focuses on
what six-sigma is today and what its roots are both in Japan
and in the west and what six-sigma offers the world today [6].
Zenon Chaczko et al. introduced a process for the module
level integration of computer based systems which is based
on the Six-sigma Process Improvement Model, where the
goal of the process is to improve the overall quality of the
system under development [7]. Philip Stephen highlighted a
distinct methodology for integrating lean manufacturing and
six-sigma philosophies in manufacturing facilities [8].
Thomas Pyzdek focuses that helps the user identify worthy
projects and move them steadily to successful completion, the
user identify poorly conceived projects before devoting any
time or resources to them, the user identify stalled projects
and provide them with the attention they need to move
forward again, the user decide when it’s time to pull the plug
on dead projects before they consume too much time and
resources and provide a record for the user that helps improve
the project selection, management and results tracking
process.
2.3 Six Sigma Improvement Approach
The main thing of Six Sigma is to taking the existing product,
process and improves them in a better way. It is a very
powerful approach to achieve the financial goals for the
organization and improving the company’s value by the
following;
Data driven
Project based
Disciplined and systematic
Customers focused (internal & external)
Success of every organization is dependent on, how to
introduce and implement Six Sigma in the organization. For
clear understanding, “Six Sigma Onion” is a best example for
showing the process of implement Six Sigma in the
organization
2.4 Process Capability
Sigma value increases the process performance in a better
way. Another way of measure the process capability and
performance by the statistical measurements like Cp, Cpk, Pp
and Ppk. The Six Sigma means a 3.4 % defects part per
million or yield of 99.9997% (perfect parts). Following is the
table of comparison of different Sigma values at different
defects part per million and capability of process here [9].
Table 2.1 Six Sigma Value Chart
SIGMA DPMO COPQ CAPABILITY
6 sigma 3.4 <10% of sales World class
5 sigma 230 10 to 15% of sales
4 sigma 6200 15to 20% of sales Industry Average
3 sigma 67000 20 to 30% of sales
2 sigma 310000 30 to 40% of sales Non Competitive
1 sigma
DPMO- Defects per Million Opportunities
COPQ- Cost of poor Quality
2.5 DMAIC
The DMAIC methodology uses a process-step structure.
Steps generally are sequential; however, some activities from
various steps may occur concurrently or may be iterative.
Deliverables for a given step must be completed prior to
formal gate review approval. Step Reviews do occur
sequentially. The DMAIC five steps are
Step1. DEFINE the problem and scope the work effort of the
project team.
Step2. MEASURE the current process or performance.
Figure 2.1 DMAIC Methodology
International Journal of Engineering and Technology (IJET) – Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1058
Step3. ANALYZE the current performance to isolate the
problem
Step4. IMPROVE the problem by selecting a solution.
Step5. CONTROL the improved process or product
performance to ensure the target(s) are met.
A DMAIC project typically runs for a relatively short
duration (three to nine months), versus product development
projects (using UAPL or DFSS) and operational line
management (using LMAD), which can run years. Given the
relatively shorter duration to other types of Six Sigma
methodologies, we distinguish the DMAIC as having five
steps, rather than phases.
2.6 Analysis Tool
2.6.1 Process Block Diagram
In order to visualize the changes required to convert raw
materials into a finished product, it is necessary to specify the
basic transformations that define the production process. The
same is true in representing the major steps involved in
offering a service [10]. Each of the basic transformations
corresponds to a stage in the process and can be accomplished
in a variety of ways depending on technologies available and
the economic and other restrictions to the problem. A block
diagram displays the structure of the process in the broadest
possible terms. The number of stages depends on the
complexity of the product and the extent of vertical or
horizontal integration in the organization. A typical process
block diagram for one way communication process is shown
below:
2.6.2 Production Layout
In developing a layout for an operation system the optimum
allocation of space is seek to the components of production
process. The best arrangement of facilities are tried to
determine and equipment capable of satisfying anticipated
demand at lowest cost. In layout all elements of a process
must be integrated. Special care must be taken to create an
environment conducive to high productivity and the
satisfaction of social and psychological needs of the people at
work. The layout of a production floor plays an important
role in the formulation of groups of people and
communication links with peers, superiors and subordinates.
For existing system the proposed layout must satisfy
constraints from existing buildings, docks and other physical
structure that form part of the production process. Sometimes
difficulties encountered in the production layout phase make
it necessary to revise previous decisions on product and
process design so that in an iterative fashion management can
arrive at an “optimum” combination of decisions for all facts
of the system- design problem [10].
2.6.3 Cause and Effect Diagram
Cause & effect diagram is a common tool in improvement
projects. It is also known as Ishikawa diagram after its
originator or as a fishbone diagram. This tool is used to come
up with new ideas like in a brainstorming session but in a
more balanced way. It is often used as input to a Design of
Experiments. A type of cause &effect diagram has an input of
x variables, both noise and control variables and an output of
variables.
Figure 2.2 A Typical Cause & Effect Diagram
Encoding Transmission Decoding Reception
International Journal of Engineering and Technology (IJET) – Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1059
2.7 Improvement Tool
2.7.1 5s
5s is a program developed by the Japanese. It is a series of
activities designed to organize the work environment so that
everything is visual and problems aren’t covered up. While
5S system improves the quality and safety, it provides
effective company organization and focuses on the
simplification of work environment and the minimization of
wastes principles. It is expressed by five Japanese words that
express cleaning and order at the company and accepting this
as work discipline. These words are:
Seiri: Sort
Seiton: Set in Order/Straighten
Seiso: Shine/Sweep
Seiketsu: Standardize
Shitsuke: Sustain/Self-discipline
The greatest feature of 5S approach is that it is simple; for
that reason it easily finds area of application. Forming a
ground for the other improvement activities, 5S is an
important term that carries priority in improvement at a
company. The liability and failure, if available, in this kind of
a change belongs to the administration, not to the personnel.
If the personnel recognize the importance of the innovation
and developments to be realized, then the established system
will be operated in a healthier manner. [11]
2.7.2 Supermarket
Supermarkets are particularly effective at addressing the
Muda caused by transport and unnecessary movement. As
supermarket come closer to the line-side and reduce the Muda
caused by unnecessary movement and transport.
Supermarkets also reduce the Muda caused by waiting.
Supermarkets are never fixed. The supermarket typically
comprises meat, fresh produce, dairy, and baked goods
departments, along with shelf space reserved for canned and
packaged goods as well as for various non-food items such as
household cleaners, pharmacy products and pet supplies.
Supermarkets usually allocate large budgets to advertising,
typically through newspapers. They also present elaborate in-
store displays of products.
2.7.3 Kaizen
Kaizen was created in Japan following World War II. The
word Kaizen means "continuous improvement". It comes
from the Japanese words 改 ("kai") which means "change" or
"to correct" and 善 ("zen") which means "good".
Kaizen is a system that involves every employee - from upper
management to the cleaning crew. Everyone is encouraged to
come up with small improvement suggestions on a regular
basis. This is not a once a month or once a year activity. It is
continuous. Japanese companies, such as Toyota and Canon,
a total of 60 to 70 suggestions per employee per year are
written down, shared and implemented.
Kaizen involves setting standards and then continually
improving those standards. To support the higher standards
Kaizen also involves providing the training, materials and
supervision that is needed for employees to achieve the
higher standards and maintain their ability to meet those
standards on an on-going basis. [12]
2.7.4 Line Balancing
Line balancing is the assignment of work to station in a line
so as to achieve the desired output rate with the smallest
number of workstations. Normally, one worker is assigned to
a station. The line that produces at the desired pace with the
fewest worker is the most efficient one. Achieving this goal is
much like the theory of constraints, because both approaches
are concerned about bottleneck. Line balancing differs in how
it addresses bottlenecks. Rather than, (1) taking on new
customer orders to best use bottleneck capacity or (2)
scheduling so that bottleneck resources are conserved, line
balancing takes a third approach. It creates workstation with
workloads as evenly balanced as possible. It seeks to create
workstations so that the capacity utilization for the bottleneck
is not for the higher than for the other workstations in the
line. Another difference is that line balancing applies only to
line processes that do assembly work or to work that can be
bundled in many ways to create the jobs for each workstation
in the line.
The analyst begins by separating the work into work
elements, which are the smallest units of work that can be
performed independently. The analyst then obtains the time
standard for each element and identifies the work elements,
called immediate predecessors that must be done before the
next elements can begin [13].
3. FINDINGS OF THE STUDY
To implement six-sigma it is needed to follow DMAIC
approach step-by step. In the following sections, this
approach is briefly described for the concerned organization.
3.1 Process Definition
In this stage, the process which is needed to improve is
identified by proper investigation. To understand the whole
manufacturing process of lovely fan, a process block diagram
is shown in Figure 5 schematically including the different
stages of production. Block diagram has become a key tool in
the development of information systems, quality management
systems, and employee handbooks. Here in this stage the
processes are clearly identified and the critical process for
improvement is recognized. Though it has not been done,
benchmarking is also essential here to understand the
situation.
3.2 Process Measurement
In this measurement stage, different variables are identified to
measure. As it has been tried to improve the sigma level of
the organization, initially the present sigma level has been
measured by using an Excel based sigma calculator and it was
found that the present sigma level of the studied organization
not satisfactory and it was 3.7 only. Hence, to improve this
level, different quality improvement tools have to be
employed and the organization has to be set a milestone to
achieve.
International Journal of Engineering and Technology (IJET) – Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1060
3.3 Process Analysis
It is a very important stage to consider because lack of proper
analysis may lead to the process to a wrong way which will
deviate from the main function of improvement. In this stage,
different basic tools of quality are preferably used to analyze
the real condition of the processes. Every successful work
goes on some specific sequence. This work also completes
some specific step. After completing each successful, it is
necessary to move next step. The steps that are followed for
data analysis are:
Step 1- Find out the existing sigma level of the production
shop.
Step 2- Analysis the existing layout of the production shop.
Step 3- Analysis the existing operation sequence by the
process block diagram.
Step 4- Analysis the existing problem by cause and effect
diagram.
3.3.1 Find out The Existing Sigma Level of The
Production Shop
Sigma level is a procedure to know the existing condition of a
production shop. The calculation of sigma level is based on
the number of defects per million opportunities (DPMO). In
order to calculate DPMO, three distinct pieces of information
are required:
a) The number of units produced.
b) The number of defects opportunities per unit.
c) The number of defects.
The actual formula is:
DPMO=
(1)
For this purpose the relevant data is collected. By using this
data the defect rate of each process is calculated and
converted it into the total defect. From collected data, the
number of units produced was 240 pieces per day, the number
of defects opportunities per unit was 5 and the number of
defects was average 18 pieces per day. Finally this
information is put into sigma level calculator. This
automatically finds the DPMO of the production shop which
is 15000. The sigma level calculator used to find the sigma
level is shown following:
After plotting the required information into sigma level
calculator, the calculator shows that the sigma level of the
production shop is 3.7.
3.3.2 Analysis The Existing Layout of The Production
Shop
The layout problem presents a challenge to management
because of the complex interactions of several key factors and
the difficulty in assessing their impact on the system
performance. The production layout is used this research for
the following purpose:
Placing equipment in a position resulting in its
maximum utilization (adjusting machine capability
and manpower utilization).
Reducing congestion in the flow of materials or
people through successive stages in the process (by
applying supermarket).
Providing easy access for equipment maintenance
and repair.
Creating efficient production lines for a smooth and
rapid product flow
Suitable means for fast and safe materials handling.
Maintaining best utilization of space.
Maintaining best utilization of human resources by
providing a comfortable and safe working
environment.
The production layout of the case organization is given in
Figure4.1.
International Journal of Engineering and Technology (IJET) – Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1061
Figure 3.1: Production Layout of Case Organization
3.3.3 Analysis the Existing Operation Sequence by Process
Block Diagram
After completing the successful analysis of production layout
further study is going on process block diagram. To find out
the existing problem of a complete production process, it is
more preferable to represent the operation sequence by
process flow diagram. For this purpose, the operation
sequence is analyzed and obtained a chart shown in Figure
3.2
International Journal of Engineering and Technology (IJET) – Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1062
Figure 3.2: Process Block Diagram of Case Organization
3.3.4 Analysis the Existing Problem by Cause & Effect
Diagram
To analyze a problem cause & effect diagram is one of the
best tools. After obtaining process flow diagram, the next step
is to find the root cause and sub-cause of the existing process.
The required cause & effect diagram is shown in Figure 3.3
International Journal of Engineering and Technology (IJET) – Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1063
Figure 3.3: Cause & Effect Diagram of Case Organization
3.4 Process Improvement
In this stage, improvement strategies are developed for
achieving the desired goal. According to the analysis, perfect
measures should be taken to progress the current situation. As
the major concern to implement six-sigma here in the case
organization to improve the productivity, it is highly needed
to diagnose the critical issues. For this reason 5s, supermarket
and line balancing are used to improve the current situation of
the production shop which is discussed below respectively.
3.4.1 5s
When the problem and sub- problem is known then it is very
easy to improve the existing process. One of the major
problems of the production system is disorder the materials,
tools, affluent, work-in-progress etc. It is often happened that
a worker do not find a tool or material in first time. For this
reason it spends time. Disorderly work-in-progress causes
increasing difficulty to pick up. Before applying 5s in any
organization, it is necessary to know the 5s score of the
defective product per day. The 5s score of the case
organization is given in Table 4.1.
Table 3.1: 5s score of 30 days for Case Organization
Sl No Date Defective Product 5s Score
01 11.12.2010 17 2.76
02 13.12.2010 20 2.95
03 14.12.2010 18 2.94
04 15.12.2010 17 2.94
05 16.12.2010 19 2.84
06 18.12.2010 16 2.88
07 19.12.2010 22 2.95
08 20.12.2010 13 2.92
09 21.12.2010 21 2.95
10 22.12.2010 18 2.94
11 23.12.2010 16 2.81
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12 24.12.2010 18 2.89
13 26.12.2010 21 2.95
14 27.12.2010 19 2.89
15 28.12.2010 20 2.95
16 29.12.2010 18 2.94
17 30.12.2010 17 2.88
18 01.01.2011 15 2.93
19 02.01.2011 18 2.94
20 03.01.2011 16 2.81
21 04.01.2011 18 2.89
22 05.01.2011 16 2.94
23 06.01.2011 15 2.87
24 08.01.2011 15 2.87
25 09.01.2011 20 2.95
26 10.01.2011 19 2.89
27 11.01.2011 18 2.89
28 12.01.2011 17 2.94
29 13.01.2011 17 2.94
30 15.01.2011 18 2.94
From Table 3.1, it is clearly seen that the 5s score is not so
very good in every day. Besides this average 5s score in 30
days is very poor which is 2.91.For this reason improvement
is necessary in this case. The 5s score is determined based on
some quality parameter. These are Rpm, Watt, Air
Circulation, Ampere, Bearing sound, Balancing, Body short,
Coil Cutter, Low Speed, Magnetic sound, Painting and
Bearing Housing. By applying 5s, it is possible to improve if
the organization maintains the following improvement
technique:
Sort
Importance of particular items should be ranked and
eliminated what was not needed such as chop pieces.
Shop has to clean including all cabinets and ceiling
pipes.
Old sinks and calibration stations should be
upgraded.
Entire shop would be painted with special industrial.
Set in order
Repositioned air tools, grinder and electrical
stations, making processes more efficient.
Proper labels for all materials should be developed.
Functional placement for storage and retrieval of
materials should be created.
Each employee should be assigned an individual
workstation.
Shine
Daily inspections of work areas and equipment have
to perform.
Trash and foreign matter should be eliminated from
the workstations and keep area clean on a continuous
basis.
Standardize
The area has to maintain with consistent operations.
Clear, simple and visual cues should be used to
detect abnormalities.
Sustain:
Weekly team meetings should be held to discuss
accomplishments and opportunities for
further improvements.
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Applying 5s score totally depends on the step sustain. It is not
possible to improve after completing first four steps without
sustain. So the case organization will only improve if sustain
is properly maintained.
3.4.2 Supermarket
To solve work-in-progress disordering, supermarket is used
as an improving tool.
Figure 3.4: Applying Supermarket of Case Organization
International Journal of Engineering and Technology (IJET) – Volume 3 No. 12, December, 2013
ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1066
By applying supermarket, the following benefits are obtained:
a) Supermarket reduces the hazards of the production shop.
b) It helps to find out materials easily.
c) It helps to find out tools for the first time.
d) It reduces the floor space and best utilization of floor
space.
The running way of case organization is too much complex
with the criteria of time and distance. So the main purpose of
this undergraduate research paper is to deal with these
obstacles and reducing time & distance as well as increasing
the production rate, ultimately defects rate will fall down.
There are almost 18 defects which are occurring everyday due
to some lacking of existing layout. The main reasons are
improper sorting, heavy working pressure of each worker,
disorderly move of some workers, performing critical task
with small space and bottleneck processes. So if anyhow it is
possible to reduce the causes, it is possible to reduce amount
of damage product and simply it can be done successfully by
applying 5s & supermarket. 5s and supermarket have
smoothly solved the above causes which are discussed in the
section of 4.4.1 and 4.4.2.
3.4.3 Line Balancing
The industries must produce momentous quantities in shorter
lead times. Product is highly correlated with high level of
productivity; production floor should be balanced in shorter
possible time and effective way for each style and quantity.
The focal constraint against the higher productivity is the
difference in individual capacity which is the mode of
improper line balancing and bottle neck process. This paper is
based on an effective layout model where to hit upon the
bottleneck process through benchmark capacity. The research
shows that this balanced layout model has increased the
efficiency by 19% and labor productivity by 73%.
3.4.3.1 Procedure of Line Balancing
The paper is discussed comparing the productivity and
efficiency before and after applying the balancing technique.
Considering experience, capacity, production line is selected.
Two important attributes have been considered, one is
possible standard method for each process and another is
considerable time in between the input has been fed to actual
individual capacity of each worker. The time is recorded to
make each process for each and every worker to find out the
number of operator and individual capacity. To find out the
(standard allowable minute) S.A.M value, process wise
capacity has been calculated, in addition to that the target,
benchmark capacity, actual capacity, labor productivity and
line efficiency are calculated. Line has been balanced
considering the bottleneck and balancing process where the
balancing process has shared the excess time after the
benchmark production in the bottleneck process. After
balancing, new manpower has been proposed and final
capacity of each worker has been reallocated. We have
compared the line graph after balancing the line, labor
productivity and line efficiency. Finally a proposed
production layout has been modeled with balanced capacity.
3.4.3.2 Equations
The following equations are used for line balancing:
Target = *
100% (2)
Labor Productivity =
(3)
Machine Productivity =
(4)
Line Efficiency=
* 100% (5)
3.4.3.3 Calculations
Table 3.2 Labor and Machine Productivity and Line
Efficiency Before Balancing the Line.
Total output per day 240 Pieces
Total manpower 98
Working time 480 minutes
SAM 126.05 minutes
Labor productivity 2.45
Machine
productivity
8.28
Line efficiency % 64.31
Process wise capacity of each work station has been found
where Standard allowable minutes (S.A.M) has been
calculated. The above table show the target per hour for the
line calculating total 98 manpower worked on that line for
480 minutes with a S.A.M value of 126.05. The Bench mark
target have standardized of 298 pieces of production at 80%
efficiency. Observation before balancing the line has been
reflected as labor and machine productivity is 2.45 and 8.28,
line efficiency is 64.31%.
3.4.3.4 Bottleneck process
Some variations are identified in process capacity from the
bench mark target and the lower capacity from the bench
mark target is the bottleneck process as production flow
would stick on the bottleneck point. Comparing total capacity
of each process to the 80% bench mark target, the bottleneck
processes have identified named Pressing 1, Pressing 2,
Binding and Grinding, marked red color.
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3.4.3.5 Balancing process
Balancing method is very essential to make the production
flow. Considering working distance, type of machines and
efficiency, workers who have extra time to work after
completing their works, have been shared their work to
complete the bottleneck processes.
Table 3.3 Balancing Process
Shifted
manpower
From To
Process No Time Process
No
Time
1 9 36 4 24
1 10 42 5 18
1 12 20 7 40
1 22 50 16 10
Operator who work in Process no. 9 Hydraulic pressing, have
been worked for 36 minutes per hour in her first process,
capacity 42 pieces and then have been worked in the process
no. 4 pressing 1 for last 24 minutes to make additional 12
pieces for overall capacity of 42 pieces on process no. 4.
Similarly Process no. 10 shaft pushing have been worked for
42 minutes and rest 18 minutes have been worked on process
no. 5 pressing 2 to make total capacity of 39 pieces which
was originally 30 pieces. Process no.12 and 22 have been
similarly worked on the process no.7 and 16 for the capacity
of 43and 41 pieces per hour.
3.5 Process Control
After taking appropriate actions for improving the process, it
has been checked again. On the basis of the results of this
assessment, previous steps may be repeated to achieve the
desired level. It is not possible always to get success at the
first time, so recurring of all the steps will lead the process to
be set at the preferred point.
Figure 3.5: Proposed Layout for the Case Organization
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4. RESULTS & DISCUSSIONS
The used improvement tools have helped to improve in this
production line. Basically 5s and supermarket is the visually
applicable tool so it is not possible to show improvement
graphically by using these two tools. But if any organization
can follow these tool that have discussed above then the
organization must be improved.
Changing from traditional layout to balanced layout model,
there are considerable improvements have moved which are
given below:
Table 4.1 Bench Mark Target, Labor and Machine Productivity and Line Efficiency After Line Balancing
Total output per day 312 Pieces
Total manpower 98
Working time 480 minutes
SAM 126.05 minutes
Target/Hour 373 100% efficiency
Target/Hour 298 80% efficiency Bench Mark
Target/Hour 223 60% efficiency
Target/Hour 149 40% efficiency
Labor productivity 3.18
Machine productivity 10.75
Line efficiency % 83.60
In a day we have boost up the production up to 312 and with
manpower of 98, line efficiency has been improved from
64.31% to 83.60% which is shown in above table. The Bench
mark target have standardized of 298 pieces of production at
80% efficiency.
There were some uncertainties in the validity and reliability
of the sampled data. These were based on the assumption .As
the main purpose of this research is to increase productivity,
it has been tried to achieve this by improving the level of
sigma. Though this case study has been conducted in a fan
manufacturing organization, the procedures and the outcomes
will be suitable for any manufacturing organization. During
the study not all the information was collected instantly, but
some previous records have been also used for better
understanding.
The DMAIC problem solving approach has helped to reach
measurable results and conclusions. An incitement to develop
feasible solutions is created by this methodology. The
magnitude of this research paper has restricted the possibility
to implement all suggested improvements. It is seemed that a
project of smaller magnitude would have been more suitable
in order to complete the control phase in full. This method is
endorsed since it is easy to apply and provides a structured
approach to problem solving.
During this research paper, key information and experience
was accessible, giving a better overall view and a more
effective progress. By doing this, it is possible to access a
much greater base of knowledge and improve morale. This is
done when “everyone”, from operating personnel to
management, feels that they are part of the solution.
All the charts and diagrams used here are drawn carefully to
show the real scenario of the case organization. The
organization is trying itself to improve its productivity, but
without using appropriate tools and techniques, it is almost
impossible to make that happen.
5. CONCLUSION AND
RECOMMENDATIONS
5.1 Conclusion
The six-sigma framework provides an impetus for
establishing best practice with the company. It also provides
the company with a performance benchmark on which it
could base its future performance enhancement programs. As
it has been observed that the level of its sigma is not
satisfactory, there is no way to improve this by DMAIC. The
implementation of six-sigma will save money which will
result higher profit of the organization. As the businesses are
influenced by globalization, the competition is arising more
and more and so, to sustain in the global business every
organization needs to maintain appropriate quality level. This
study will contribute to a new management approach on
improving business process for both efficiency and consistent
quality customer service. After reviewing the benefits and
limitations behind Six Sigma, a company should determine
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whether or not Six Sigma is for them. A clear trend is that Six
Sigma is diversifying into large service oriented
organizations. In the case organization it is noted that the
workers are very busy to produce their expected amount of
fan. Almost all time they perform repetitive task which waste
time. As a result, sometimes they produce defective fan. By
applying 5s and supermarket, it is possible to reduce
repetitive task by saving time which have shown on data
analysis. Consequently, there is less possibility for producing
defective fan which is the main target of six-sigma. On the
other hand by applying line balancing, productivity increases
from 240 to 312 per day by reducing defect. Finally it is said
that, it is possible to improve productivity by using six-sigma
which is the main purpose of this study. In the future, it is
likely that more changes will emerge; making Six Sigma an
even more beneficial application for organizations of all types
and sizes. It is believed that other companies can learn the
insights from this study to identify further research areas for
efficiency and quality services. To ensure this quality and
also the sustainability, six-sigma will no doubt play a vital
role in the long run.
5.2 Recommendations for Future Research
There are several approaches to choose from when the goal is
to increase the productivity of a fan manufacturing company.
The techniques used in this research paper have been limited
due to insufficient time and resources. In this research paper
only 5s, supermarket and line balancing are used as
improvement. These have given a better solution. But if any
one uses other technique of industrial engineering then he
will get more benefit than this research paper . If it is decided
to use the data in future studies it would be interesting .By
this way it may be possible to specify high productivity. The
quest for higher productivity will never stop and the project
extreme fan manufacturing will proceed. An important
suggestion for future work is to test if the findings are
applicable to other products and machines within the factory.
A deeper understanding could possibly make the conclusions
from this study more understandable and easier to apply to
other products.
Result would have been more effective if we would have
taken some large quantity order and balancing the process is
highly related to the type of machines as machine utilized in
bottleneck and balancing process should be similar.
Further improvements in the productivity can be achieved by
considering large amount of order minimum 10000pieces.
The new bench mark target which can be the further chance
of improvements to balance the line with this new bench
mark target. Proposed layout model has been followed the
logic of modular system (one worker works more than two
processes who is skilled on all processes and these
combination of skilled workers finish their work in piece flow
production) and traditional system (one worker works in one
process and all the workers who may be skilled or not finish
their work in bundle flow production) both together where
only modular production system can be applicable with a
series of skilled workers to achieve more productivity. On
this occasion, skilled workers are eligible for the production
processes and proper training and supervision is essential to
achieve the optimum improvements on productivity and
efficiency.
REFERENCES
[1] Stevenson WJ,2005, ‘Competitiveness, Strategy and
Productivity’, Richard T. Hercher,Jr, Wanda J,
Zeman, ‘Operations Management’ 8th
edition,
McGraw-Hill/Irwin, a business unit of the McGraw-
Hill companies, Inc, 1221 avenue of the Americas,
New York, NY,10020,p (47-53).
[2] Park, SH, 2003, ‘Six Sigma for Quality and
Productivity Promotion’, Asian Productivity
Organization, Japan.
[3] Siddhartan Ramamoorthy, 2003, ‘Lean Six Sigma
Applications In Aircraft Assembly’, B.E, Mechanical
Engineering, University of Madras, India.
[4] Soković, M., Pavletić, D., and Krulčić, E., Six Sigma
process improvements in automotive parts
production, Journal of Achievements in Materials and
Manufacturing Engineering, Vol. 19 No. 1, pp 96-102
(2006),
[5] Nyrén G., A Six Sigma project at Ericsson Network
Technologies, Master’s Research paper , MSc
Programmes in Engineering, Luleå University of
Technology (2007),
[6] Racine J., A Directed Research Project of the
Evolution of Six Sigma, Master’s Research paper ,
MBA Program, Strayer University (2005),
[7] Chaczko Z., Rahali E., and Tariq R., The Apllication
of Six Sigma to Integration of Computer Based
Systems, World Academy of Science, Engineering
and Technology 34, pp 332- 337 (2007),
[8] Stephen, P., Application of DMAIC to Integrate Lean
Manufacturing and Six Sigma, Master’s Research
paper , MSc in Industrial and Systems Engineering,
Virginia Polytechnic Institute and State University,
(2004),
[9] Abid,M.A.,Rehman, A.U., and Anees, M, 2010, “
How to minimize the defect rate of final
product in textile plant by the implementation of
DMAIC tool of six-sigma”,a program of “Master of
Industrial Engineering-Quality and Environmental
Management”, University of BORAS, School of
Engineering.
[10] Dervitsiotis, K.N., Graduate school of Industrial
Studies, Thessaloniki, Greece, 1981,Operations
Management, McGraw-Hill.Inc, United states of
America.
[11] Korkut,D.S., Cakicier, N., Erdinler,E.S,2009, “5s
activities and its application at a sample company”,
by Ulay, G., Duzce University, Faculty of Forestry,
Department of Forest Industrial Engineering,
Duzce,81620, Turkey, Istanbul University, Faculty of
Forestry, Department of Forest Industrial
Engineering, Istanbul, Turkey,CAD Engineer,
Numarine Yacht Company, Istanbul Turkey and
Forest Industry Engineer, Duzce, Turkey.
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ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1070
[12] www.graphicproducts.com/tutorial/kaizen
[13] Krajewski, L.J, University of Notre Dame, Ritzman
L.P, The Ohio State University and Boston College,
Malhotra M.K, University of South Carolina,2007,
Operations Management Processes and Value Chains,
8th
edition, Pearson Education ,Inc.
APPENDIX
The 5s Score Of 30 Days For Case Organization
5s score for the date of 11.12.2012
The 5s score of the day is 2.76
5s score for the date of 13.12.2012
The 5s score of the day is 2.95
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5s score for the date of 14.12.2012
The 5s score of the day is 2.94
5s score for the date of 15.12.2012
The 5s score of the day is 2.94
5s score for the date of 16.12.2012
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The 5s score of the day is 2.84
5s score for the date of 18.12.2012
The 5s score of the day is 2.88
5s score for the date of 19.12.2012
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The 5s score of the day is 2.95
5s score for the date of 20.12.2012
The 5s score of the day is 2.92
5s score for the date of 21.12.2012
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The 5s score of the day is 2.95
5s score for the date of 22.12.2012
The 5s score of the day is 2.94
5s score for the date of 23.12.2012
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The 5s score of the day is 2.81
5s score for the date of 24.12.2012
The 5s score of the day is 2.89
5s score for the date of 26.12.2012
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ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1076
The 5s score of the day is 2.95
5s score for the date of 27.12.2012
The 5s score of the day is 2.89
5s score for the date of 28.12.2012
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The 5s score of the day is 2.95
5s score for the date of 29.12.2012
The 5s score of the day is 2.94
5s score for the date of 30.12.2012
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The 5s score of the day is 2.88
5s score for the date of 01.01.2013
The 5s score of the day is 2.93
5s score for the date of 02.01.2013
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The 5s score of the day is 2.94
5s score for the date of 03.01.2013
The 5s score of the day is 2.81
5s score for the date of 04.01.2013
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ISSN: 2049-3444 © 2013 – IJET Publications UK. All rights reserved. 1080
The 5s score of the day is 2.89
5s score for the date of 05.01.2013
The 5s score of the day is 2.94
5s score for the date of 06.01.2013
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The 5s score of the day is 2.87
5s score for the date of 08.01.2013
The 5s score of the day is 2.87
5s score for the date of 09.01.2013
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The 5s score of the day is 2.95
5s score for the date of 10.01.2013
The 5s score of the day is 2.89
5s score for the date of 11.01.2013
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The 5s score of the day is 2.89
5s score for the date of 12.01.2013
The 5s score of the day is 2.94
5s score for the date of 13.01.2013
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The 5s score of the day is 2.94
5s score for the date of 15.01.2013
The 5s score of the day is 2.94
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