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Value Stream Mapping
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Value Stream Mapping
We have discussed the principles of lean
manufacturing Need a tool for analyzing the value stream
One of the first steps on the journey to lean
is Value Stream Mapping.
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Value Stream Mapping (cont.)
Planning an efficient road trip involves the
use of a map. First one looks at the current location.
Next the destination is located
Finally, directions are made for getting there.
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Value Stream Mapping (cont.)
A similar process should be followed for
companies planning an efficient road tripfor lean manufacturing.
The tool used for evaluating the current
state (current location) and planning thefuture state (destination) is Value Stream
Mapping.
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Value Stream Mapping (cont.)
Value Stream Mapping (VSM) provides a
visual representation of every process in thematerial and information flow of a product
(Rother & Shook, 1999).
A current state map is first created Establishes a companys location at the
beginning of the lean journey.
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Value Stream Mapping (cont.)
A future state map is then created which
illustrates where the company wishes to beafter the first lean initiatives have been taken.
Next an action plan is created and thenexecuted.
The entire mapping process is then repeatedagain and again in a never ending continuousimprovement cycle.
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Value Stream Mapping (cont.)
VSM can be done at various levels. Start
with the single plant level.
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Levels of a Value Stream
Across Companies
Process Level
Multiple Plants
Single Plant(door to door)
(Rother & Shook, 1999)
Begin Here
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Creating the Current State Map
Developing a future begins with an analysisof the current production situation.(Rother and Shook,18)
Process:
Spend 1-2 weeks on shop floor to understand process
Pencil and Paper in hand (computers add necessarytime and effort)
Bring a stopwatch; do not rely on standard data.
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Value Stream Mapping
The icons used for VSM and their definition
are given next.
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(Rother & Shook, 1999)
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Process and Data Boxes Each process is placed in a
process box.
Each process box has adata box that shouldinclude:
cycle times
machine uptime
# operators
changeover times
C/t=0.5 hour
C/O= 0.1 hr
Uptime=90%
Machining
1
1 operator
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Inventory
Inventory adds
unnecessary costs Increases lead time
Takes up space in the
plant By establishing Pull,
inventory is greatly
reduced or removed
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Information Flow
Ususally when mapping, flow of material
(parts, jobs, ) is what most people consider
Another flow is important: Information flow
Need to map both material and information
flow in a VSM.
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(Rother & Shook, 1999)
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(Rother & Shook, 1999)
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(Rother & Shook, 1999)
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(Rother & Shook, 1999)
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Value Stream Mapping
A completed current state map for Acme
Stamping is shown on the next slide. Theicons and measurements will be explained
later.
(Rother and Shook)
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Current State Map Example
(Rother and Shook, 21)
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Mapping Tips
Collect current-state information while following the material
and information flow yourself.
Begin at shipping and work upstream
Start with process that is most closely linked to customer
Do not rely on standard times or information that you do not
personally obtain
Bring a stopwatch
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Mapping Tips (cont.)
Map the entire value stream yourself
If different people map pieces of value stream, no
one will understand entire stream.
Always draw in pencil
Create sketch right on the shop floor.
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Value Stream Mapping
The following slides explains some of the
measurements associated with lean.
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Future State Mapping
After constructing the current state map, you will next
construct the future state map.
Purpose of Future State Map
Highlight sources of waste
Eliminate by implementing future-state value stream
Goal: Build a chain linking individual processes to
customer by continuous flow or pull.
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Future State Mapping (cont.)
Eliminate as much inventory as possible
Rearrange processes into U-shaped cells
Set up a pull system from the customer
Define TAKT time
Set-up Supermarkets with Kanbansinstead of inventories.
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Guidelines for a Lean Value Stream
1. Produce to your TAKT time.
Synchronize pace of production with pace of
sales
Requires effort:
Provide fast response (within TAKT) to
problems
Eliminate causes of unplanned downtime
Eliminate change-over time in downstream
processes
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TAKTTime
TAKT
TIME =
Cycle Time = TAKT time
(ideal for future state)
(Liker, 145)
Your Available Work Time per ShiftCustomer Demand Rate per Shift
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TAKTTime Example
TAKT
TIME=
27,000 sec
500 pieces
Customer is buying product at a rate of one every 54
secondsThis is the target rate for production
= 54 seconds
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Guidelines for a Lean Value Stream (cont.)
2. Develop continuous flow whereverpossible.
Produce one piece at a time
Pass product immediately to next step
Most efficient way to produce
In future state map, combine processboxes wherever you create continuousflow.
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(Rother & Shook, 1999)
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(Rother & Shook, 1999)
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Guidelines for a Lean Value Stream (cont.)3. Use supermarkets to control production where continuous
flow does not extend upstream.
Spots where continuous flow is not possible and batching
is necessary: Processes that operate at very fast or slow cycle times and need
to change over to serve multiple families (e.g. stamping orinjection molding)
Suppliers are far away and one piece shipping is not realistic
Processes with too much lead time or that are too unreliable
NOTE: Resist temptation to schedule via an independentscheduling function.
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(Rother & Shook, 1999)
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Guidelines for a Lean Value Stream (cont.)
4. Try to send the customer schedule to only
one production process.
Schedule the Pacemaker Process Pacemaker Process = Process that sets the production
rate for all upstream processes
In future-state map the pacemaker is the
production process that is controlled by theoutside customers orders
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(Rother & Shook, 1999)
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Guidelines for a Lean Value Stream (cont.)5. Distribute the production of different products evenly over
time at the pacemaker process. (Level the production mix)
Usually products are scheduled in long runs to reduce changeover
times Causes longer lead times
Causes higher inventories
The more level the production mix, the quicker you can
respond to customer requirements
With short lead time
With little finished goods inventory
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Guidelines for a Lean Value Stream (cont.)6. Create an initial pull by releasing and
withdrawing small, consistent increments ofwork at the pacemaker process. (Level the
production volume) Creates predictable production flow
Enables quick corrective action
Regularly release a small, consistent amount of
production instruction (5-60 minutes worth) Simultaneously, take away equal amounts of
finished goods
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Guidelines for a Lean Value Stream (cont.)
7. Develop the ability to make every part every
day in fabrication processes upstream of the
pacemaker process. Must shorten changeover times
Must run smaller batches
Allows quicker response to downstream
requirements
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Value Stream Mapping
Using the previous guidelines, a future state
map can be constructed. The next slide shows a completed future
state map of the example.
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F
uture State Example
Production
Lead = 4.5 days
Time
Value-
Added = 169 sec.
Time
.
EPE = 1 Shift
C/O < 10 min.
Production Control
Stamping
Staging
Shipping
Welding/
Assembly
Takt = 60 sec.
C/O = 0
Uptime = 100%
2 Shifts
Total work
content = 168 sec
Michigan
Steel Co.
18,400 pcs/mo
-12,000 L
-6,400 R
Tray= 20 pieces
2Shifts
State Street
Assembly
90/60/30 day
Forecasts6 week
Forecast
Daily
Order
Daily
Order
Daily
(Milk Run)
1X
Daily
20
Daily Order
OXOX
2020
20
L
R
20
totebatch
Coils
c
oil
coil
1.5 days 1 sec. 1 day 168 sec. 2 days
Changeover
Weldchangeover
Weld
uptime
(Rother & Shook, 32)
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After Value Stream Mapping
Once the future state map has beencompleted, the next step is to create anaction plan for reaching the future state.
The planning and execution of the actionplan may involve the use ofKaizen teams.
After the action plan has been executed,another current state map is drawn and theentire process repeated.
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Perfection
Continuous Improvement- the process ofincrementally and continually decreasing thewaste in the production and adding value.
Kaizen is the Japanese term for ContinuousImprovement and the term commonly used
in Lean Manufacturing. (Miller , 75)
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References Allen, J. (2000, June) Make lean manufacturing work for you.
Manufacturing Engineering pp. 54-56.
Associated Press (1991). Important dates in Compaq ComputerCorp.s history. The Associated Press. 10/25/1991
Bodek, N. (1988). Foreword. In T. Ohno, Toyota ProductionSystem: Beyondlarge-scale production (pp. ix-xii). (ProductivityInc, Trans.). Portland, OR: Productivity Press (Original workpublished 1978).
Becker, J.E. (2001, August) Implementing 5S: To promote safety &housekeeping. Professional Safety29
CNBC (1998). CEO of Dell Computer delivers statement on marketpower and structural change in the software industry before theSenate Judicial committee. CNBC/Dow Jones Business Video.3/03/1998
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References Connstep, Inc. (2002).Glossaryof Lean Manufacturing Terms.
Retrieved October 30, 2002, from Connstep Web site:www.connstep.org/web/content.nsf/webpages/Programs_LM
de Wardt, J.P. (1995). Brief: lean drilling introducing theapplication of automotive lean manufacturing techniques to well
construction. Journalof Petroleum Technology,47(2), 113-114.
Georgia Tech Economic Development Institute (1999). DefinitionsandTerms. Retrieved October 1, 2002, fromGeorgia TechEconomic Development Institute Web site:www.industry.gatech.edu/lean/leanmanuf_defs.html
Lean ManufacturingGlossary.(n.d.). Retrieved July 29, 2002 from:www.lean1.org/services/glossary.cfm
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References
Leflar, J.A. (2001). Practical TPM: Successful equipmentmanagement at Agilent Technologies. Portland, OR: ProductivityPress
Liker, J. (1998). Introduction: Bringing lean back to the U.S.A. In J.Liker (Ed.), Becoming Lean (pp.3-48). Portland, OR: ProductivityPress
Miller, B., Schenk, V. (2001). Glossary. All I needto knowaboutmanufacturing I learnedin Joes garage. (pp. 73-81) Bayrock Press
Ohno, T. (1988). Toyota Production System: Beyondlarge-scaleproduction (Productivity Inc, Trans.). Portland, OR: ProductivityPress (Original work published 1978).
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References
Productivity Press Development Team. (1996). Quick changeoverforoperators: The SMEDsystem. Portland, OR: Productivity Press
Reary, Bob (2002). A supervisors guide to integrated demand
and supply. Journalof Business Forecasting Methods & System. 3(7/01/2002)
Robinson, C. (2001). Total Productive Maintenance. In J. Allen, C.Robinson, & D. Stewart (Eds.), Lean Manufacturing:A plant floorguide.(pp. 325-355). Dearborn, MI: Society of ManufacturingEngineers.
Rother, M., Shook, J. (1999). Learning to See. Brookline, MA: TheLean Enterprise Institute.
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References
Search Manufacturing (2000). Lean ManufacturingGlossary.
Retrieved October 1, 2002, from Search Manufacturing Web site
www.searchmanufacturing.com/Manufacturing/ Lean/glossary.ht
m
Shook, J. (1998). Bringing the Toyota Production System to the
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Becoming Lean (pp.41-69). Portland, OR: Productivity Press.
Standard, C., & Davis, D. (1999). Running todays factory.
Cincinnati, OH: Hanser Gardner Publication.
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References
Thomerson,G. (2001). Visual Factory. In J. Allen, C. Robinson & D.
Stewart (Eds.) Lean manufacturing: a plant floor guide. Dearborn,
MI: Society of Manufacturing Engineers.
Womack, J. (1998). Foreword. In J. Liker (Ed.), Becoming Lean
(pp. xiii xvi). Portland, OR: Productivity Press.
Womack, J., & Jones, D. (1996). Lean thinking. New York: Simon &
Schuster.
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