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Value Stream Mapping
Learning to See
Mike Rother and John Shook
The Lean Enterprise Institute
Version 1.2 1999
ISBN 0-09667843-0-8
www.lean.org
What is Value Stream Mapping?
A value stream is all actions (both value added and non-value added) currently required to bring a product through the main flows essential to every product:
1. The production flow from raw material to the customer
2. The design flow from concept to launchWhat follows focuses on the production flow
from customer demand back through to raw material which is the flow usually related to lean manufacturing.
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Total Value Stream
Suppliers Factory or Company
Customer to End User
focus
• Value stream mapping is a pencil and paper tool that helps visualise and understand the flow of material and information as a product makes its way through the value stream
• A map is created by following a product’s production path from customer to supplier and carefully drawing a visual representation of every process in the material and information flow.
• Then by asking a set of key questions draw a “future state” map of how value shouldflow.
Why Value Stream Mapping is an Essential Tool
• It helps visualise more than just a single-process level.
• It helps you see more than waste. It helps you see the sources of waste in the value stream,
• It provides a common language for talking about the manufacturing process
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Why Value Stream Mapping is an Essential Tool
• It makes decisions about the flow apparent.
• It ties together lean concepts and techniques, which helps avoid cherry picking.
• It forms the basis of an implementation plan -by designing the whole door-to-door flow it becomes a blueprint for lean implementation
Why Value Stream Mapping is an Essential Tool
• It shows the linkage between the information flow and material flow.
• Value stream mapping is a qualitative tool by which you describe in detail how the facility should operate in order to create flow. Numbers are good for creating a sense of urgency or as before or after measures. Value stream mapping is good for describing that you are actually doing to affect those numbers.
Material and Information Flow
• The movement of material through a factory usually comes to mind but there is another flow - of information - that tells each process what to make or what to do next.
• The essential question is: How can we make information flow so that one process will make only what the next process needs when it needs it?
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information
material
PRODUCTION FLOW
Value Stream Mapping StepsProduct Family
Current State Drawing
Future State Drawing
Work Plan and Implementation
Selecting a Product Family
• The first step in value stream mapping is to focus on one product family. Value stream mapping means walking and drawing process steps (material and information) for one product family from door to door.
• A family is a group of products that pass through similar processing steps and over common equipment.
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1 2 3 4 5 6 7 8 A X X X X XB X X X X X XC X X X X X X D X X X X XE X X X X X F X X X X XG X X X X X
Assembly Steps and Equipment
Prod
ucts
Selecting a Product Family
A Product Family
The Value Stream Manager
• To avoid isolated islands of functionality one person should lead responsibility for understanding a products family's value stream and improving it.
• Mapping and future state implementation needs to be led by someone who can see across the boundaries over which a product’s value stream flows and make change happen there.
• The value stream manager should report directly to senior management
Process 1 Process 2 Process 3kaizen
Customer
kaizen
The Value Stream Manager is Responsible for the Value Stream
kaizen
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Two Kinds of Kaizen
senior mgmt
front lines
focus
FLOW KAIZEN(Value Stream Improvement)
PROCESS KAIZEN(Elimination of Waste)
• Both flow kaizen (value stream improvement) and process-level kaizen (elimination of waste at the shop floor team level) are necessary - improvement in one improves the other.
• Flow kaizen focuses on material and information flow (which requires a high vantage point to see) and process kaizen focuses on people and process flow.
Two Kinds of Kaizen
Using the Mapping Tool
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Initial Value Stream Mapping StepsProduct Family
Current State Drawing
Future State Drawing
Work Plan and Implementation
Using The Mapping Tool
• The first step is drawing the current state map which is done by gathering information from the shop floor.
• Future state ideas will come from mapping the current state. Likewise drawing the future state will often point out important current-state information which has been overlooked.
Using The Mapping Tool
• The final step is to prepare and begin actively using an implementation plan that describes on one page how to plan to achieve the future state.
• Then as the future state becomes reality, a new future state map should be drawn.
• That’s continuous improvement at the value stream.
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THE CUURENT STATE MAP
Drawing the Current State Map
Initial Value Stream Mapping StepsProduct Family
Current State Drawing
Future State Drawing
Work Plan and Implementation
Drawing the Current-State Map
• Developing the future state begins with an analysis of the current production situation. Mapping begins at the level of door-to door-flow where you draw process categories like assembly or welding instead of recording each process step.
• Once you see the overall flow through the plant, you can change the level of magnification; zooming in to a map every individual step within a process category, or zooming out to encompass the value stream external to the plant.
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Process Level
Single Plant(door to door)
Multiple Plants
Across Companies
Levels of Mapping the Value Stream for a Product Family
begin here
Drawing the Current-State Map
• As noted in Lean Thinking, the critical place to begin any improvement effort is a clear specification of the value of the product as perceived by the customer.
• Otherwise you can run the risk of improving a value stream which efficiently provides the end customer with something other than what’s really wanted. Thus mapping begins with customer requirements.
Drawing the Current-State Map
• Material Flow is drawn from left to right on the bottom half of the map in order of processing steps; not according to the physical layout of the plant.
• Value stream mapping uses seconds for cycle times, takt times and available working times.
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A Few Mapping Tips
• Always collect current-state information walking along the actual pathways of material and information flows.
• Begin with a quick walk along the entire door-to-door value stream
• Begin at the shipping end and work upstream
A Few Mapping Tips
• Begin your stopwatch and do not rely on
standard times or information that you do
not obtain personally
• Map the whole value stream yourself
• Always draw by hand in pencil
Typical Process Data
• C/T (cycle time)
• C/O (changeover time)
• uptime (on demand machine uptime)
• EPE (every product every…… production batch sizes)
• number of operators
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• Number of product variations
• Pack size
• working time (minus breaks)
• scrap rate
Typical Process Data
Some Lean Measurements
(C/T)
Cycle Time (C/T)How often a part or product is actually completed by a process as timed by observation. Also, the time it takes an operator to go through all of their work elements before repeating them.
Cycle Time
Some Lean Measurements
Value Added Time (VA)
Time of those work elements that
actually transform the product in a way
the customer is willing to pay for.
VA Time
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Some Lean MeasurementsLead Time (L/T)The time it takes
one piece to move all the way through the process or a value stream from start to finish. Envision timing a marked part as it moves
from beginning to end
Lead Time
or
usually
VA < C/T < L/T
VALUE STREAM MAPPING ICONS
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Material Icons
Manufacturing Process
AssemblyOne process box equals an area of
flow. All processes should be labelled.
Also used for departments such
as production control.
Outside Sources
XYZ Corporation
Used to show customers,
suppliers and outside
manufacturing processes
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Data Box
Used to record information concerning a
manufacturing process,
department, customer etc
C/T = 45 secC/O = 30 minUptime = 80%
3 shifts2% scrap
Inventory
Count and time should be notedI
300 pieces 1 day
Truck Shipment
Note frequency of shipments
Mon + Wed
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Movement of Production Material by PUSH
Material that is produced and
moved forward before the next process needs it; usually based on
schedule
Movement of Finished Goods to Customer
Supermarket
A controlled inventory of parts that is
used to schedule production at an
upstream process
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Withdrawal
Pull of materials, usually from a supermarket
Transfer of controlled quantities of material between processes in “First-In-First-Out” Sequence
Indicates a device to limit quantity and ensure FIFO flow of material
between processes. Maximum quantity should be noted
FIFOMax 20 pieces
Information Icons
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Manual Information Flow
For example: production schedule or
shipping schedule
Electronic Information Flow
For example via electronic data
interchange
Information
Describes an information flow
Weekly Schedule
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Withdrawal Kanban
Card or device that instructs the
material handler to get transfer parts
(ie from a supermarket to the consuming process)
Signal Kanban
The “one per batch” kanban. Signals when
a reorder point is reached and another
batch needs to be produced, Used where
supplying process must produce in batches because
changeovers required
Sequenced Pull Ball
Gives instruction to immediately produce a
predetermined type and quantity, typically one unit. A pull system
for subassembly processes without
using a supermarket
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Kanban Post
Place where kanban are
collected and held for
conveniance
Kanban Arriving in Batches
Load Levelling
Tool to intercept batches of kanban and
level the volume and mix of them over a
period of time
OXOX
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“Go See” Production Scheduling
Adjusting schedules based on checking inventory
levels.
General Icons
Kaizen Lightening Burst
Highlights improvement needs
at specific processes that are critical to achieving the value stream. Can be used
to plan kaizen workshops
weld changeover
welder uptime
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Buffer or Safety Stock
“Buffer” or “Safety Stock” must be noted
Operator
Represents a person viewed from above
THE CURRENT STATE MAP
EXAMPLEACME Stamping
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First View of the Current State Map Showing the Customer
State Street Assembly
18,400 p c s/mo- 12,000 L- 6,400 R
Tray = 20 pieces2 Shifts
Coils5 days
I I I I I I
C/T = 39seconds
27,600 sec avail2 shifts
Uptime = 100%C/O = 10 minutes
C/T = 1 second
EPA = 2 weeks27,600 sec availUptime = 85%
C/O = 1 hourC/T = 46seconds
27,600 sec avail2 shifts
Uptime = 80%C/O = 10 minutes
C/T = 62seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
C/T = 40seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
2700 L1440 R
1200 L640 R
1600 L850 R
1100 L600 R
4600 L2400 R
ASSEMBLY #2ASSEMBLY #1 SHIPPINGS. WELD #2S. WELD #1STAMPING
Staging1 1 1 1 1200 T
Second View of the Current State Map with all the Processes, Data Boxes and Inventory Triangles
State Street Assembly
18,400 p c s/mo- 12,000 L- 6,400 R
Tray = 20 pieces2 Shifts
Coils5 days
I I I I I I
C/T = 39seconds
27,600 sec avail2 shifts
Uptime = 100%C/O = 10 minutes
C/T = 1 second
EPA = 2 weeks27,600 sec availUptime = 85%
C/O = 1 hourC/T = 46seconds
27,600 sec avail2 shifts
Uptime = 80%C/O = 10 minutes
C/T = 62seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
C/T = 40seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
2700 L1440 R
1200 L640 R
1600 L850 R
1100 L600 R
4600 L2400 R
ASSEMBLY #2ASSEMBLY #1 SHIPPINGS. WELD #2S. WELD #1STAMPING
Staging1 1 1 1 1200 T
State Street Assembly
18,400 p c s/mo- 12,000 L- 6,400 R
Tray = 20 pieces2 Shifts
1xDaily
Michigan Steel Co.
Tues + Thur
500 ft coils
Third View of the Current State Map showing the Material Flow
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Coils5 days
I I
C/T = 39seconds
27,600 sec avail2 shifts
Uptime = 100%C/O = 10 minutes
C/T = 1 second
EPA = 2 weeks27,600 sec availUptime = 85%
C/O = 1 hourC/T = 46seconds
27,600 sec avail2 shifts
Uptime = 80%C/O = 10 minutes
C/T = 62seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
C/T = 40seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
2700 L1440 R
1200 L640 R
1600 L850 R
1100 L600 R
4600 L2400 R
ASSEMBLY #2ASSEMBLY #1 SHIPPINGS. WELD #2S. WELD #1STAMPING
Staging1 1 1 1 1200 T
State Street Assembly
18,400 p c s/mo- 12,000 L- 6,400 R
Tray = 20 pieces2 Shifts
1xDaily
Michigan Steel Co.
Tues + Thur
500 ft coils
PRODUCTION CONTROL
MRP
Weekly Schedule
Daily Ship Schedule
Daily Order
30/60/90 day forecasts
6 week forecasts
Weekly fax
I I I I
Fourth View of the Current State Map with Information Flows and Push Arrows
Coils5 days
I I
C/T = 39seconds
27,600 sec avail2 shifts
Uptime = 100%C/O = 10 minutes
C/T = 1 second
EPA = 2 weeks27,600 sec availUptime = 85%
C/O = 1 hourC/T = 46seconds
27,600 sec avail2 shifts
Uptime = 80%C/O = 10 minutes
C/T = 62seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
C/T = 40seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
2700 L1440 R
1200 L640 R
1600 L850 R
1100 L600 R
4600 L2400 R
ASSEMBLY #2ASSEMBLY #1 SHIPPINGS. WELD #2S. WELD #1STAMPING
Staging1 1 1 1 1200 T
State Street Assembly
18,400 p c s/mo- 12,000 L- 6,400 R
Tray = 20 pieces2 Shifts
ProductionLead Time=23.6 days
ProductionLead Time=23.6 days
5 days
1 second
7.6 days 1.8 days 2.7 days 2 days 4.5 days
39 seconds 46 seconds 62 seconds 40 seconds
1xDaily
Michigan Steel Co.
Tues + Thur
500 ft coils
PRODUCTION CONTROL
MRP
Weekly Schedule
Daily Ship Schedule
Daily Order
30/60/90 day forecasts
6 week forecasts
Weekly fax
I I I I
Completed Current State Map with Lead-Time Bars and Data
Coils5 days
I I
C/T = 39seconds
27,600 sec avail2 shifts
Uptime = 100%C/O = 10 minutes
C/T = 1 second
EPA = 2 weeks27,600 sec availUptime = 85%
C/O = 1 hourC/T = 46seconds
27,600 sec avail2 shifts
Uptime = 80%C/O = 10 minutes
C/T = 62seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
C/T = 40seconds
2 shiftsUptime = 100%
C/O = 0
27,600 sec avail
2700 L1440 R
1200 L640 R
1600 L850 R
1100 L600 R
4600 L2400 R
ASSEMBLY #2ASSEMBLY #1 SHIPPINGS. WELD #2S. WELD #1STAMPING
Staging1 1 1 1 1200 T
State Street Assembly
18,400 p c s/mo- 12,000 L- 6,400 R
Tray = 20 pieces2 Shifts
ProductionLead Time=23.6 days
ProductionLead Time=23.6 days
5 days
1 second
7.6 days 1.8 days 2.7 days 2 days 4.5 days
39 seconds 46 seconds 62 seconds 40 seconds
1xDaily
Michigan Steel Co.
Tues + Thur
500 ft coils
PRODUCTION CONTROL
MRP
Weekly Schedule
Daily Ship Schedule
Daily Order
30/60/90 day forecasts
6 week forecasts
Weekly fax
I I I I
Completed Current State Map with Lead-Time Bars and Data