Value Stream Mapping - HCMUTntdung_ise/Material/Lean... · 1 Value Stream Mapping Learning to See Mike Rother and John Shook The Lean Enterprise Institute Version 1.2 1999 ISBN 0-09667843-0-8

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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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• 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


• 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




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




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


• 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.


• 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



C/T = 62seconds

2 shiftsUptime = 100%

C/O = 0

27,600 sec avail

C/T = 40seconds


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


18,400 p c s/mo- 12,000 L- 6,400 R


Coils5 days

I I I I I I

C/T = 39seconds



C/T = 1 second





C/T = 62seconds


C/O = 0

27,600 sec avail

C/T = 40seconds


C/O = 0

27,600 sec avail

2700 L1440 R

1200 L640 R

1600 L850 R

1100 L600 R

4600 L2400 R


Staging1 1 1 1 1200 T


18,400 p c s/mo- 12,000 L- 6,400 R


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



C/T = 1 second





C/T = 62seconds


C/O = 0

27,600 sec avail

C/T = 40seconds


C/O = 0

27,600 sec avail

2700 L1440 R

1200 L640 R

1600 L850 R

1100 L600 R

4600 L2400 R


Staging1 1 1 1 1200 T


18,400 p c s/mo- 12,000 L- 6,400 R


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



C/T = 1 second





C/T = 62seconds


C/O = 0

27,600 sec avail

C/T = 40seconds


C/O = 0

27,600 sec avail

2700 L1440 R

1200 L640 R

1600 L850 R

1100 L600 R

4600 L2400 R


Staging1 1 1 1 1200 T


18,400 p c s/mo- 12,000 L- 6,400 R


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


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



C/T = 1 second





C/T = 62seconds


C/O = 0

27,600 sec avail

C/T = 40seconds


C/O = 0

27,600 sec avail

2700 L1440 R

1200 L640 R

1600 L850 R

1100 L600 R

4600 L2400 R


Staging1 1 1 1 1200 T


18,400 p c s/mo- 12,000 L- 6,400 R




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


6 week forecasts

Weekly fax

I I I I

Completed Current State Map with Lead-Time Bars and Data

Documents

Value Stream Mapping - HCMUTntdung_ise/Material/Lean... · 1 Value Stream Mapping Learning to See Mike Rother and John Shook The Lean Enterprise Institute Version 1.2 1999 ISBN 0-09667843-0-8