Value Stream Mapping - MDH 2 Daniel VSM... · Definition 4 • Value stream mapping (VSM) is one of the basic methods within Lean, in order to understand and communicate the material

Value Stream Mapping 2014-09-09 Daniel Gåsvaer

Content

2

Introduction and overview Presentation material VSM

Exercise Templates

Objective and content of the module

• To create an understanding of what a value stream map (VSM) is and how to use it

• Learn how to develop a current state and future state VSM diagram

Content

•  Introduction and overview

•  Presentation material VSM

Ø Current state VSM Ø Future state VSM

•  Exercise

Ø Current state map

•  Template

Definition

4

• Value stream mapping (VSM) is one of the basic methods within Lean, in order to understand and communicate the material and information flow for a product, plant or supply chain

•  It is a helpful way to identify sources of waste and opportunities for improvement as well as supporting the design process for future production flows

• Always create a VSM for a value stream before diving into the task of waste elimination

The origins of value stream mapping lie at Toyota

5

●  5 Taichi Ohno’s problem •  Managed a machine shop •  Had a large area of responsibility •  Had an unsatisfied customer •  Could not see waste or flow at a glance

The Solution •  Needed a standard method for visual

flow mapping – Value Stream Mapping was used

Suppliers

Daily ��sequence list

Shipping list

Stores

Shared

Filtered ��sequence list

FIFO

T

T

PI PW

Dedicated

ANC Line

Shared

FIFO

T

T

PI PW

Filtered ��sequence list

FIFO

Production Control

Levelling Board

T

Customers

Headset Line

Transducer Line

Dispatch

A VSM is always a clear, single-sheet overview

6

●  6

The detail of a VSM is adjusted according to the level of application (e.g. across supply chain or across one factory)

Overview Detail Description

VSM is focusing on two types of flows which can be observed in any business environment

7

Company

Information

Material

Raw material ��orders

Work ��orders

Shipping ��schedule

Customer ��orders

Market ��forecasts

Raw ��materials

Sub ��assembly Assembly Finished ��

parts

Supplier Customer

VSM is a method of viewing the combination of flows, and this is the way it looks like

8

Taking a view on the complete value stream – not just one process – enables optimization of the entire system

9

Why do value stream mapping?

10

Why shorten the lead time? ●  Eliminate waste

●  The longer time it takes to complete a product, the more cost increases and quality decreases

●  Shorten the lead time will lower the cost and increase the quality ●  Your problems are no longer hidden in the inventories ●  Long lead time implies higher risk of products being damaged while stored ●  Long lead time also implies risk of decreased customer demand on products in

progress

●  Shorten time from order to delivery will make you more responsive to customer demands

●  Shortening the lead times gives: ⇒  Lower WIP ⇒  Lower inventory ⇒  Increased cash flow ⇒  Increased possibilities for investments

11

Quality

Cost

Symbols – VSM provides a common language for describing manufacturing processes and discussing improvement opportunities

12

Who should use VSM

• The Value Stream Manager, e.g., the person who is responsible for the value stream of the product, from supplier to customer

• VSM is led by a person who is trained in the method

• A cross-functional team with representatives from production, manufacturing engineering, quality, maintenance etc. supports the VSM leader

• The result of the VSM is used by the people who are planning and implementing the improvements

13

Two types of VSM diagrams

14

Objectives

Purpose

• Show a holistic view of the entire ��current system

• Highlight waste and its sources ��throughout the system

•  Identify improvement opportunities • Provide common picture for discussion

• Provides a detailed visual description of the current value stream

• Force best practice in creating a vision of the ideal lean value stream

• Set baseline for tactical implementation planning by identifying future value stream loops

• Assist in quantifying improvement potential

• Serve as communication tool for the future state

• Provides a detailed visual description of a redesigned value stream

When to use the Value Stream Mapping cycle

15

•  Map the value streams for your product families before diving into the task of waste elimination

•  When the current state map is created, create a realistic future state map and start to plan and implement the identified improvement steps.

•  After implementation, when the future state VSM has become the current state, a new future state map should be drawn

•  And the value stream mapping cycle keeps going…

Content

16


Ø Current state VSM –  How to create it –  Hints

Ø  Future state VSM Ø  Examples Ø Moving forward

Exercise Templates

Select a product family ●  Select a product or a product family to map ●  Focus on one product/product family for each VSM ●  A product family is a group of products that pass

through similar processing steps and over common equipment in your downstream processes

17

A current state VSM is created in 7 steps

18

•  Draw customer •  Add data boxes

•  Draw each process in order of process flow

•  Draw inventories between processes

•  Collect and add process data Ø Cycle times

Ø Process times Ø Machine uptime Ø Changeover

time

Ø Batch size Ø No of shifts Ø Etc.

•  Inventory, FIFO or supermarket

•  Count/estimate level of Ø Raw material Ø WIP Ø FG

•  Calculate stock turns

•  Delivery receipt frequency

•  Customer delivery frequency

•  Determine whether flow is push or pull

•  Draw push arrow as needed

•  Add production control information from/to customers and suppliers

•  Add information arrows internally and externally

•  Do the calculations Ø Lead time Ø Processing

time Ø Value adding

time

Determine customer requirements

Draw process steps

Gather process data

Gather inventory data

Determine material flows

Draw information flows

Calculate lead time

Step 1: Determine customer requirements

•  Draw in customer

•  Add customer data box: – Quantities of orders per variant – Order size (minimum, maximum, average) – Packaging size –  Shipment schedules – Customer lead time – Order adjustments

19


Draw process steps

Gather process data




Calculate lead time

Company

Packaging quantity 2 shifts

Amount/year

Step 2: Draw process steps and inventory

20


Draw process steps

Gather process data




Calculate lead time

Drilling

I

● Draw all process steps Ø  A process is an activity where material can stagnate on

either side Ø  A process is not the same as a department or function Ø  Parallel processes are to be drawn above each other Ø  A box can be drawn around processes in the department Ø To distinguish stations on a line, use multiple data boxes

● Draw inventories, where they exist, between processes including inventory before and after production

Step 2: Draw process steps and inventory

21

I I I I I

Cutting

1

Welding No 1

1

Welding No 2

1

Assembly No 2

1

Despatch dep. Assembly No 1

1

Despatch dep.

I

Company

12000 Left 6400 Right

18400 pcs/month

Box: 20pcs 2 shifts


Draw process steps

Gather process data




Calculate lead time

Step 3: Gather process data

22


Draw process steps

Gather process data




Calculate lead time

•  Add process data box: – Machine and manual cycle times – Process time – Changeover time – Machine uptime – Available time (scheduled time – management allowances) –  Batch size – Number of operators – Number of product variations –  Shipment quantities and timing (supplier and finished goods) –  Scrap and re-work rate –  Shared or dedicated process

C/O = 3600 sec Uptime = 80%

C/T = 72 sec

Drilling

1

These are the most important

Step 3: Definitions (1/2)

●  Cycle time (C/T) ●  Time that elapses between one part is coming off the process until the next part

is coming off ●  Process time (P/T) ●  Equals the time one unit needs in the process. It is equal to C/T if one unit is

processed at a time ●  Changeover time/Set-up time (C/O) ●  The time it takes to change from producing one product variant to another

●  Machine uptime ●  The available time for a machine when maintenance and breakdown time is

subtracted 23


Draw process steps

Gather process data




Calculate lead time

Step 3: Definitions (2/2)

●  Available time ●  Scheduled working time minus brakes

●  Number of operators ●  The number of operators it takes to run the process

●  Shared or dedicated process ●  Is the process dedicated to this specific product or is it shared with other value

streams?

24


Draw process steps

Gather process data




Calculate lead time


25


Draw process steps

Gather process data




Calculate lead time


26


Draw process steps

Gather process data




Calculate lead time

I I I I I

Company

Cutting

1

C/O = 1 hour Uptime = 85%

C/T = 1 Sec

Welding No 1

1

C/O = 10 mjn Uptime = 100%

C/T = 39 sec

C/O = 10 min Uptime = 80%

C/T = 46 sec

Welding No 2

1


C/T = 40 sec

Assembly No 2

1

Despatch dep.


C/T = 62 sec

Assembly No 1

1

Despatch dep.


18400 pcs/month

Box: 20pcs 2 shifts

I

Step 4: Gather inventory data

● Use inventory symbol if inventory is not controlled

● Controlled inventory is either FIFO or supermarket

27

I 300 pcs

FIFO

Supermarket


Draw process steps

Gather process data




Calculate lead time

Step 4: Gather inventory data

28


Draw process steps

Gather process data




Calculate lead time

Company


18400 pcs/month

Box: 20pcs 2 shifts

Cutting

1


C/T = 1 Sec

L: 4600 pcs��R: 2400 pcs

Welding No 1

1


C/T = 39 sec

L: 1100 pcs��R: 600 pcs

L: 1600 pcs��R: 850 pcs

L: 1200 pcs��R: 640 pcs


C/T = 46 sec

Welding No 2

1


C/T = 40 sec

Assembly No 2

1

Despatch dep.

L: 2700 pcs��R: 1440 pcs


C/T = 62 sec

Assembly No 1

1

Despatch dep.

I 5 days of production ��demand

I I I I I

Step 5: Determine material flow -external

•  Draw in main supplier(s) •  Add data box for supplier •  Draw deliveries from supplier and to customer •  Add data box for frequency of deliveries and box size

Typical information •  Order size (minimum, maximum, average) •  Packaging size •  Shipment schedules •  Customer lead time •  Order adjustments

29


Draw process steps

Gather process data


Determine external material flows

Draw internal material and information flows

Calculate lead time

Company

Packaging quantity

Amount/year

1 day

Transport

Customer/ supplier flow

Step 5: Determine material flow -internal

● Draw push or pull systems as appropriate

● Draw suitable pull trigger symbols

30


Draw process steps

Gather process data




Calculate lead time

OXOX 20

Sequenced-pull ball

Load leveling

Withdrawal kanban

Production kanban

Signal kanban

Batch based kanban

►Pull flow Push flow

Step 5: Material flow

31


Draw process steps

Gather process data




Calculate lead time

►►►►►

Company

Cutting

1


C/T = 1 Sec

Welding No 1

1


C/T = 39 sec


C/T = 46 sec

Welding No 2

1


C/T = 40 sec

Assembly No 2

1

Despatch dep.


C/T = 62 sec

Assembly No 1

1

Despatch dep.


18400 pcs/month

Box: 20pcs 2 shifts


L: 4600 pcs��R: 2400 pcs

L: 1100 pcs��R: 600 pcs

L: 1600 pcs��R: 850 pcs

L: 1200 pcs��R: 640 pcs

L: 2700 pcs��R: 1440 pcs

I I I I I

Company

Supplier

Tuesday, Thursday

1700 m/roll Raw Material

1 x day

Step 6: Draw information flows

32


Draw process steps

Gather process data




Calculate lead time

Manual information flow

Electronic information flow

● Add right type of information flow arrows

● Add receivers of info (systems and departments

Step 6: Rate information flow – Pulling or pushing

33


Draw process steps

Gather process data




Calculate lead time

Push The most common push situation is that no required rate information is communicated, material is just pushed in at the beginning. Daily quotas may be measured

When MRP is implemented, push occurs as different rates are communicated, based on non-perfect assumptions

Pull Pull occurs when rate information is communicated through a signal from the immediate customer (downstream) process, so pulling material flow

Step 6: Internal material and information flows

34


Draw process steps

Gather process data




Calculate lead time

Company

Supplier Company

1 x day

Tuesday, Thursday


►I ►I

Cutting

1


C/T = 1 Sec

►I L: 4600 pcs��R: 2400 pcs

Welding No 1

1


C/T = 39 sec

L: 1100 pcs��R: 600 pcs

L: 1600 pcs��R: 850 pcs

►I L: 1200 pcs��R: 640 pcs


C/T = 46 sec

Welding No 2

1


C/T = 40 sec

Assembly No 2

1

Despatch dep. ►I L: 2700 pcs��R: 1440 pcs


C/T = 62 sec

Assembly No 1

1

Despatch dep.



18400 pcs/month

Box: 20pcs 2 shifts

Production planning 90/60/30 days forecast

Daily delivery schedules Daily

faxes

Daily delivery ��schedule

Weekly production schedule

6 weeks forecast

MPS

35

Step 7: Calculate lead time Determine customer requirements

Draw process steps

Gather process data




Calculate lead time

•  Draw the trace along the bottom of the diagram

•  Calculate inventory lead times and add these to the trace together with process times

•  Calculate value adding time (%)

•  Look at the details of the trace to find the worst contributors to lead time

•  If mapping a product family: Choose the longest component stream in the product family and calculate total processing time and lead time for that product

P/T

Inventory L/T

P/T P/T

Inventory L/T

Sum of processing time

Sum of manufacturing lead time = Value adding ratio of the time the

product spends in the factory

Step 7: Exercise in calculating lead time

36


Draw process steps

Gather process data




Calculate lead time

62 s 40 s

2.7 days 2 days The sum of machine + manual processing time including current waste Note: Do not divide the time by the number of parts unless one part can be produced, e.g., oven curing 200 parts for 24 hours, is a processing time of 24 hours, not 7.2 min

•  Takt time = available time per shift / customer demand per shift

•  Inventory lead time = takt time * inventory

•  Inventory lead time (days) = inventory lead time (h) / available hours per day

27600 sec / (18400 pcs / (20 days * 2 shifts)) = 60 sec (1 item is finished each 60 sec)

60 * 1840 = 110400 sec , which is equal to 30.2 h

30.2 / (7.7 h * 2 shifts) = 2 days

Customer demand 18400 pcs/month Working days/month 20 days Available time/day 15.4 hours (2 shifts) TAKT 60 sec/pcs Inventory 1840 pcs (1200+640) Inventory lead time (sec) 110400 sec (1840*60) Inventory lead time (h) 30.2 h (110400 s/3600 s) Inventory lead time (days) 2 days (30.2 h/15.4 h) Individual parts may be expedited, or left behind, but this gives an accurate calculation of total lead time

Troughs are “floor-to-floor” time

Peaks show the inventory lead time

Step 7: Lead time

37


Draw process steps

Gather process data




Calculate lead time

Company

Supplier

Production planning

Company

90/60/30 days forecast

Daily delivery schedules Daily

faxes

Daily delivery ��schedule

Weekly production schedule

1 x day

Tuesday, Thursday

6 weeks forecast

MPS


►I ►I

Cutting

1


C/T = 1 Sec

►I L: 4600 pcs��R: 2400 pcs

Welding No 1

1


C/T = 39 sec

L: 1100 pcs��R: 600 pcs

L: 1600 pcs��R: 850 pcs

►I L: 1200 pcs��R: 640 pcs


C/T = 46 sec

Welding No 2

1


C/T = 40 sec

Assembly No 2

1

Despatch dep. ►I L: 2700 pcs��R: 1440 pcs


C/T = 62 sec

Assembly No 1

1

Despatch dep.


5 days 7.6 days 1.8 days 2.7 days 2 days 4.5 days

1 sec 39 sec 46 sec 62 sec 40 sec

L/T: 23.6 days

V/A: 188 sec


18400 pcs/month

Box: 20pcs 2 shifts

Content

38


Ø Current state VSM ‒  How to create it –  Hints

Ø  Future state VSM Ø  Examples Ø Moving forward

Exercise Templates

Content

39


Exercise

Ø Current state map – The Factory Templates

The Factory (1/9) General information ●  The Factory produces several components for tractors. This case concerns one product

family –steering arms, which are produced in many configurations. The Factory’s customers for this product family are both original-equipment tractor builders and the aftermarket repair business

●  Because of the wide variety of product configurations and the fact that customer configuration requirements vary from order to order, steering arms are a “make-to-order” business. It currently takes a customer order 27 days to get through The Factory’s production processes. This long lead time and a significant order backlog have prompted The Factory to quote a 60-day lead time to customer. However, The Factory’s customers cannot accurately predict their size requirements more than 2 weeks out, and thus they make adjustments to their orders 2 weeks before shipment. These order adjustments lead to order expediting on the shop floor at The Factory

●  Although The Factory Production Control releases customer orders to production roughly in the order that they are received, orders are batched by product configuration on the shop floor to reduce the number of time-consuming changeovers. This also creates a need for order expediting

The Factory (2/9) The Product ●  A steering arm is a metal rod with a forged fitting welded to each end ●  The Factory’s steering arms are available in 20 different lengths, 2 diameters, and

with 3 different types of end fittings. Each end of the steering arm can have a different fitting. This means there are 240 different steering arm part numbers that The Factory supplies

Customer requirements ●  24,000 pieces per month ●  A customer order ranges from 25 to 200 pieces, with an average of 50 pieces ●  Corrugated-box packaging with up to 5 steering arms in a box ●  Several daily shipments per day by truck to various customers ●  Each customer’s configuration requirements vary greatly from order to order ●  The Factory requires orders to arrive 60 days before shipping date ●  Customer often adjust their size mix 2 weeks before the shipping date 41

The Factory (3/9)

Production Processes ●  The Factory’s processes for the steering arm product family involve cutting

metal rod followed by welding end fittings to the rod, deflash (machine removal of excess weldment), painting at an outside vendor, and subsequent assembly of the end fittings. The forged end-fitting sockets are also machined at The Factory. Finished steering arms are staged and shipped to customers on a daily basis

42

Cut rods Weld one end

Weld other end

Remove flash

Paint outside vendor

Assembly

Machine forgings

The Factory (4/9)

Production Processes (cont.) ●  Switching between rod lengths requires a 15 minute changeover at the cutting,

welding and deflash operations ●  Switching between rod diameters takes a 1 hour changeover at the cutting,

welding and deflash operations. The longer changeover for diameters is due mostly to an increased quality-control inspection requirement

●  Switching between the three types of forged end fittings takes a 2 hour changeover at the machining operation

●  Steel rods are supplied by the The Steel Company. The lead time for obtaining rods is 16 weeks. There are two shipments per month

●  Raw forgings for the end fittings are supplied by The Casting Company. The lead time for obtaining forgings is 12 weeks. There are two shipments per month

43

The Factory (5/9) Work time ●  20 days in a month ●  2 shift operation in all production departments ●  8 hours every shift, with overtime if necessary ●  Two 15-minute breaks during each shift (manual processes stop during breaks) ●  Unpaid lunch The Factory Production Control Department ●  Receives customer orders 60 days out and enters them to MRP ●  Generates one “shop order” per customer, which follows the order through the entire

production process ●  Releases shop orders to production 6 weeks before shipment to accelerate MRP’s

procurement of rods and forgings ●  Issues daily priority list to production supervisors. Supervisors sequence shop orders

through their departments according to this list ●  Receives customer size-changes 2 weeks before shipment and advises supervisors to

expedite these orders ●  Issues daily shipping schedule to Shipping Department 44

The Factory (6/9) Process information 1. Cutting (shared process = the saw cuts rods for many different products)

Manual process with one (1) operator Cycle time: 15 sec Changeover time: 15 minutes for length, 1 hour for diameter Reliability: 100 % Observed inventory: 20 days of uncut rods before the saw, 5 days of cut rods

2. Welding workstation 1 (dedicated to this product family)

This operation welds the first machined forging to the rod Automatic process, with operator load and unload external to machine cycle Cycle time: 10 sec for operator, 30 sec for machine Changeover time: 15 minutes for length, 1 hour for diameter Reliability: 90 % Observed inventory: 3 days of welded arms

45

The Factory (7/9) 3. Welding workstation 2 (dedicated to this product family)

This operation welds the second machined forging to the rod Automatic process, with operator load and unload external to machine cycle Cycle time: 10 sec for operator, 30 sec for machine Changeover time: 15 minutes for length, 1 hour for diameter Reliability: 80 % Observed inventory: 3 days of welded arms

4. Deflash workstation

Automatic process, with operator load and unload external to machine cycle Cycle time: 10 sec for operator, 30 sec for machine Changeover time: 15 minutes for length, 1 hour for diameter Reliability: 100 % Observed inventory: 5 days of deflashed arms

46

The Factory (8/9)

5. Painting (steering arms are shipped to an outside vendor for painting) Painting lead time: 2 days One daily truck pickup pf unpainted arms and drop-off of painted arms Observed inventory: 2 days at the painter, 6 days of painted arms at The Factory

6. End-fitting Assembly (dedicated to this product family)

Manual process with 6 operators Total work time per piece: 195 sec Changeover time: 10-minute fixture swap Reliability: 100 % Observed finished-goods inventory in warehouse: 4 days of finished steering arms

47

The Factory (9/9)

7. Machining of forgings Automatic machining process with one machine attendant Cycle time: 30 sec Changeover time: 2 hours Reliability: 100 % Observed inventory: 20 days of raw forgings from the supplier, 4 days of machined forgings

8. Shipping Department

Removes parts from finished goods warehouse and stages them for truck shipment to customer

●  Given this information about the production at The Factory

- try now to create a current state map!

48

Leanspelet

•  Ett exempel på tillämpning av Lean

•  Exemplet är från produktion, men…

•  …Lean handlar om hela företaget

Foto från Swerea IVF

49

Press

Montering

Värmebehandling

Kvalitetskontroll

Lager/leverans

Kund

Planering

Material- hantering

Leanspelet

50

Exempel VFA nuläge – Leanspel 1.0

Kunden •  Kunden Langbecks Mekaniska beställer tre olika produkter; röd, gul och blå. I senare omgångar introduceras även specialare men de är inte intressanta just nu •  Kunden beställer en ny produkt var 15:e sekund. För maximal betalning ska vi kunna leverera direkt •  Totalt sker 48 beställningar varje dag •  Produktion i ett skift. Ett skift är 720 sekunder

Produktionsplaneringen •  MPS-baserat system •  Tar emot sekvensbeställningar från kunden i ett MPS-system. Dessa order går elektroniskt direkt vidare till Lager/Leverans •  Har möjlighet att välja mellan tre olika produktionsplaner. Dessa kan bytas på daglig basis. Produktionsplanen lämnas ut till funktionen Press inför varje dags start •  Aktuell produktionsplan för nulägesanalysen är 8 röda – 2 gula – 2 blå. Denna plan följer exakt kundens genomsnittliga behov över dagen •  Dagliga leveransplaner skickas elektroniskt till leverantören ”Tero Tools AB”

Givna data (1):

Lager/Leverans •  Levererar direkt till kund •  En operatör •  Varje leverans tar 7 sekunder •  Vid analysen finns 9 produkter i färdigvarulager; 3 röda, 3 gula och 3 blå Kvalitet •  Levererar kontrollerade rätta produkter till Lager/Leverans •  Kontrollerar alla produkter. Felaktiga spärras •  Varje kontroll tar 5 sekunder och sköts av en operatör •  Har vid analysen inga produkter att kontrollera

Givna data (2):

Värmebehandling/Ugn •  Levererar värmebehandlade produkter till Kvalitet i batcher om 6 produkter •  Värmebehandlar alla produkter. Ugnen har utrymme för 8 produkter och varje värmebehandling tar 60 sekunder. Det finns ingen ställtid eller andra kända störningar •  Röda produkter får inte blandas med övriga •  Har vid analysen tre obehandlade produkter i inkommande lager •  En operatör bemannar maskinen


Montering •  Levererar till Värmebehandling i batcher om 6 •  En operatör monterar, ingen ställtid eller andra kända störningar •  Montering av en komplett produkt tar 10 sekunder •  På varje produkt monteras 2 st 4-bitars och 2 st 8-bitars lego •  I inkommande lager finns vid analysen 15 vita, 9 röda och 6 blå, alla 4-bitars, samt 18 svarta, 18 vita, 18 röda och 18 blå, alla 8-bitars. Däremot saknas produkter från Press

Givna data (3):

Press •  Levererar pressade produkter till Montering i batcher om 6 •  Bemannas av en operatör. Ställtid vid färgbyte (Duplo) är 30 sekunder. Annars inga kända problem med utrustningen •  Pressning av en produkt tar 5 sekunder •  Operationen består av att en lego (4-bitars) samt en Duplo pressas ihop. •  I inkommande lager finns vid tiden för analysen totalt 28 st Duplo och 30 st 4-bitars lego (18 svarta, 6 röda, 6 blå)


Råvarulager •  Levererar material till Montering och Press. Ingen definierad batchstorlek •  Sköter materialhantering mellan de olika funktionerna. Här finns inget uttalat materialförsörjningssystem utan operatören får köra runt mellan de olika funktionerna och kontrollera om något behöver flyttas. Batchstorlekar är en lastbärare med 6 produkter mellan samtliga processer förutom mellan kvalitet och lager/leverans •  Tar emot dagliga leveranser från Tero Tools AB

Givna data (4):


Layout leanspelet:


VFA nuläge – Leanspel 1.0 Steg 1 – rita upp de ingående processerna och eventuella lager på undre halvan:

Steg 2 – fyll de olika informationsrutorna och respektive lagringspunkt med fakta:

VFA nuläge – Leanspel 1.0

Steg 3 – rita in kunder, leverantörer, transporter och typ av system för materialhantering:


Steg 4 – rita in typ av materialflöde i fabriken:


Steg 5 – rita in informationsflödet:


Steg 6 – rita in trappan värdehöjande/genomloppstid:

Värdehöjande kvot: 87/687 =0,127 = 12,7%



Content

63



–  How to create it –  Hints

Ø  Examples Ø Moving forward

Exercise Templates

A future state VSM depicts the target state of the redesigned production system

64

•  Forces end-to-end thinking

•  Breaks the system into manageable but related “loops” for implementation

•  Assists in quantifying the improvement potential

Future state map

The hardest piece: Improve the manufacturing process!

Developing an “ideal” future state map can be a useful visioning tool

65

1.  First step is to evaluate a current state map

2.  Second step is to make an visionary ideal state map, representing the vision and long term goals, without going into details

3.  Third step is to create a future state map. It should be concrete, detailed and realistic to reach within a medium term time period (6 – 18 months)

4.  Implement the immediate state through a step change improvement

5.  Improve over time, make a new value stream mapping cycle

Follow these 7 guidelines and answer key questions to develop a future state VSM

66

1. Produce to Takt time: What is the future Takt time for the chosen product family?

2. Develop continuous flow wherever possible: Where can you introduce continuous flow?

3. Use supermarkets to control production where continuous flow does not extend upstream: Will you build to a finished goods supermarket or directly to shipping? Where will you need to use supermarket pulls?

4. Try to send the customer schedule to only 1 production ��process (information entry point): At what single point will you schedule production (“Pacemaker”)?

7. Develop the ability to make “every part everyday” in upstream processes

6. Set the “pitch” at the pacemaker process by establishing a pull of small, consistent increments of work: What consistent increments of work will be released to and taken away from the pacemaker?

5. Distribute the production of different products evenly over time at the pacemaker process: How will you level the production mix at the pacemaker?

What issues could prevent you from achieving the future state design?

Guideline 1 – produce to takt time •  Takt time is the time allocated to produce one part or

product, based on the rate of sales, to meet customer requirements. It is calculated by dividing the available working time per shift (in seconds)* by customer demand per shift (in units)

•  Takt time is used to synchronize the pace of production with the pace of sales. It is a reference number that provides a sense for the pace

67 * Available work time = production time less scheduled breaks

Customer demand rate per shift Takt time =

Available production time per shift

Guideline 2 – develop continuous flow wherever possible

68

● 68

Isolated islands

A Inventory Material

B Inventory Inventory

C Inventory finished product Finished product

Continuous flow

Material A B C Finished product

Continuous flow refers to producing one piece at a time, with each item passed immediately from one process to the next without waiting in between. Continuous flow is the most efficient way to produce, and may require substantial creativity to achieve

one-piece flow balances process input to output

Guideline 3 – use supermarkets to control production where continuous flow does not extend upstream

●  There are often spots in the value stream where continuous flow is not possible and batching is necessary. There can be several reasons for this, including

Ø Some processes are designed to operate at very fast or slow cycle times and need to change over to serve multiple product families

Ø Some processes, such as those at suppliers, are physically distanced from the operation and shipping one piece at a time is not realistic

Ø Some processes have too much lead time or are too unreliable to link directly to other processes in a continuous flow

●  Instead of individual scheduling through a production control department, Kanban signals link production to downstream customer demand

69

Supermarket

Production Kanban Withdrawal Kanban

Supplying process

A Product Product

”Supermarket” is a controlled inventory of parts that is used to schedule production at an upstream process

Customer process

B

First view of future state map showing takt time, weld/assembly cell, and finished goods supermarket

70

Weld+Assy

Customer

Box = 20 items 2 shifts

18,400 pcs/month

1/day 20

C/O = 0 Sec Uptime = 100%

Takt = 60 Sec

2 shifts

Shipping

Packing

C/T: 55 sek.

Stamping

Guideline 4 – try to send the customer schedule to only 1 production process

•  By using supermarket pull systems, you will typically need to schedule only one point in the door-to-door value stream. This point is called the pacemaker process. The method in which production is controlled at this process sets the pace for all the upstream processes. All processes after the pacemaker collectively make up the customer-order-to-ship lead time

•  Material continuously flows from the pacemaker downstream to finished goods and on to customer. On the future state map, the pacemaker is the production process that is controlled by the outside customer’s orders

71

Process 1

FIFO

Pacemaker

Process 2 Process 4 Process 3

FIFO

Customer

Order-to-delivery lead time

Single point scheduling

Supermarket

Pull

Second view of future state map showing stamping and raw material supermarket

72

Weld+Assy Coils

(at the stamping��process)

batch

Production control 6-week ��forecasts

Daily Order

Stamping

Customer

Box = 20 items 2 shifs

18,400 pcs/month

Supplier

1/day

Daily

20


Takt = 60 Sec

2 shifts

Coil

Coi

l

Shipping

Packing

C/T: 55 sek.

20

1 day

Guideline 5 – distribute the production of different products evenly over time at the pacemaker process

73

A A A AA A A A B BB B B B B CC C

Shift 1 Shift 2 Shift 3

A B A CB A

Shift 1 Shift 2 Shift 3

B A B AC B A B C BA A

By leveling the product mix at the pacemaker process, you can respond to different customer requirements with reduced lead times while holding minimum inventory. This in turn reduces the size of supermarkets.

This is the symbol for leveled production:

OXOX

Guideline 6 – set the “pitch” at the pacemaker process by establishing a pull of small, consistent increments of work

74

Shift 1 7:00 7:20 7:40 8:00 8:20 8:40 9:00 9:20 Shift 2 3:00 3:20 3:40 4:00 4:20 4:40 5:00 5:20

Product A

Product B

Product C

A A

B B

C

AA

B

Establishing a consistent or level production pace creates a predictable production flow, which indicates problems and enables you to take quick corrective action. A good place to start is to regularly release only a small, consistent amount of production instruction (usually 5- to 60-minutes’ worth) ��at the pacemaker process, and simultaneously take away an equal amount of finished goods. This consistent increment of work is often called pitch

Guideline 7 – Develop the ability to make “every part everyday” in upstream processes

75

● 75

EPE ____________

“OPTIMUM” Lot size

Costs per part

Changeover costs

Inventory costs

Overall costs

By reducing changeover times, it is possible to run smaller batches and to carry less inventory

Changeover

X Lot size

By shortening changeover times and running smaller batches in the upstream processes, those processes will be able to respond to changing downstream needs more quickly. In turn, they will require even less inventory to be held in their supermarkets. EPE stands for “every part every . . .” after which you can write a time such as a week, day, shift, hour, pitch, or takt

Completed view of future state map

76

Weld+Assy

Production lead time = 5 days

Value-added time = 166 sec

1.5 days

1 sec

1.5 day

165 sec

2 days

Coils

(at the stamping��process)

batch

Production control 6-week ��forecasts

Daily Order

90-/60-/30-day forecasts

Daily order

Weld changeover

Welder uptime

Eliminate waste

Stamping

Customer

Box = 20 items 2 shifts

18,400 pcs/month

Supplier

1/day

Daily

OXOX

20 20

20


Takt = 60 Sec

2 shifts

Total work content = 165 seconds

C/O = <10 min Uptime = 85%

EPE=1 shift

27600 sec.avail.

Changeover

20 20

20

Coil

Coi

l

Shipping

Packing

C/T: 55 sek.

Daily order

1.5 days

Content

77



–  How to create it –  Hints

Ø  Examples Ø Moving forward

Exercise Templates

Practical tips for creating the future-state value stream and quantifying the improvement potential ●  Make 1-2 future-state value stream maps so you have intermediate

“check points”

●  Simplify . . . simplify . . . simplify – otherwise the maps will collect dust and the insights will be lost

●  Work closely with team members across functions, being wary not to make people “afraid” by overcomplicating the tool

●  Build the future state by selectively improving element-by-element of the current-state map

78

Content

79


Ø Current state VSM Ø  Future state VSM Ø Examples Ø Moving forward

Exercise Templates

Current state map of a machined component

80

●  81

Future state map of the same component

EXAMPLE

Content

82


Ø Current state VSM Ø  Future state VSM Ø  Examples Ø Moving forward

Exercise Templates

Moving forward –from words to action

●  Value Stream Mapping is only a tool to find improvement opportunities; real benefit is achieved when the identified improvements are carried out

●  Make an action plan, showing how to change the production process, including: ●  How to implement the identified improvements ●  When (step by step) to implement the identified improvements ●  Check points and deadlines ●  Measurable goals ●  Identified responsible people

●  Follow-up your action plan according to a fixed routine

●  Hint: Start the change in an area where the process is well-known and where the likelihood of success is high

83

Content

84


Exercise Templates

Follow four basic principles to assure a good VSM

85

•  Gather your own data; believe nothing that is given by others

•  If you see for yourself, you will understand!

•  Do not divide the flow, you must understand the end-to-end activity

•  Sketch out the flow ��as you go

•  Modify on the fly

•  Focus on the flow ��and inter-relationships, not on making it look pretty

•  First: “Walk” quickly and get a sense of the flow and sequence of processes

•  Then: “Walk” the process from customer requirements back to inputs, e.g., from shipping dock back to raw materials

•  Capture all relevant process data as you go

•  Involve people who has good knowledge about the product and the production

•  Involve people from several different functions

•  Keep the number of people at a manageable level

Walk, understand, and validate

Capture data yourself

Involve the ��right people

Use paper ��and pencil

Value stream mapping

Hints ●  Don't worry about structure on the first draft – use paper an pencil or

post-its to draw the processes and organize them

●  Keep the map visually simple, but rich enough to expose waste and problems. Use common sense to handle exceptions

●  Use the knowledge and the support of the operators

●  Check the data and information

●  While drawing the map, highlight problem areas

●  Begin at the shipping end and walk upstream

86

Template for creating a VSM

87

A large blank paper


88


89


90

Latmask •  Processtid (P/T): Tiden för ett parti, oavsett storlek, att förädlas i en operation, t ex värmebehandling eller

torkning (ex: 20 potatisar kokas i 20 minuter -> 20 min i processtid) •  Cykeltid (C/T): Stycktid för en operation (ex: 20 potatisar i 20 minuter -> 1 minut i cykeltid). Samma som P/T då

en enhet i taget förädlas i ett steg, i en seriell process •  Tillgänglighet (Uptime, U/T): Sannolikheten att vid vilken tid som helst att en resurs tillverkar eller är redo

för tillverkning •  Tillgänglig tid (Tillg tid): Vanligtvis betald arbetstid minus planerade stopp •  Takt: Kundens behov för en tidsperiod (ex 920 st/dag) •  Takttid (T/T): Tillgänglig arbetstid / kundens behov under arbetstiden (ex: 920 minuter / 920 st = 60 s) •  Ställtid (S/T): Tiden från att den sista korrekta detaljen i ett parti är klar tills den första korrekta i nästa parti är

klar •  Värdehöjning: Den tid som förädling som kunden är beredd att betala för sker, här summan av processtiden för

alla steg artikeln går igenom •  Genomloppstid/ Ledtid i produktionen: Den tid det tar för en artikel att gå igenom hela värdeflödet, från

dörr till dörr. Summan av processtiderna och tid i lager och buffert •  Ledtid: Normalt används detta begrepp för tiden mellan kundens beställning och leverans

91

Further reading

•  If you want to learn more about Value stream mapping, the book Learning to see (Rother, M. et al (1998) The Lean Enterprise Institute) is recommended

Documents

Value Stream Mapping - MDH 2 Daniel VSM... · Definition 4 • Value stream mapping (VSM) is one of the basic methods within Lean, in order to understand and communicate the material