6 7 Value Stream Mapping

Source book: Value-stream Management: eight steps to planning, mapping and sustaining lean improvements, Tapping, Luyster, Shuker,

2002)

Prepared by Dr. ule Itr Satolu 1

What is a value-stream? Manufacturing companies: finished goods

Operations are process elements that add value to the product.

Non-value adding elements

Value stream consists of everything, including non-value adding act.- that makes transformation possible!


Value-Stream Value-stream similar to a river!

Network of processes and operations through which material and information flows in time and space.

Communication all along the supply chain: information flow.

Material transport & conveyance: material flow.


Value-Stream Mapping (VSM) Map current state of production showing flow of

material and information.

Goal: To gather accurate and real-time data related to product family or value-stream.

Go to the shopfloor, and collect data. (No past reports etc.).


VSM To improve a process, you must first observe and

understand it!

Mapping a process: clean picture of wastes!

While gathering data at each point, ask how do we know what to do next? Means of communication.

Trace information and material flow!

Capturing this information is the essence of VSM.


VSM Icons

(Tapping, Luyster, Shuker, 2002) 6 Prepared by Dr. ule Itr Satolu

Mapping Current State

VSM is drawn for a part/product family!

It is like taking a picture of current state of the shopfloor.

The date VSM is drawn written on the map.

Post current state-map on the story board.

Tool for good visual communication and management!


Mapping Current State

Visualize entire flow, rather than a single operation

Visualize how currently operations communicate

Sources of wastes

Bottlenecks and WIP

Safety and equipment concerns

Common language for people

See how operation running truly!


Getting Ready 1. Draw simple sketches of main production

operations on a white board.

2. Go to the floor. Start from the most downstream operation (shipping) and collect actual process data for the key attributes!


Getting Ready Key Attributes:

Quantity of parts shipped per month and per day

Supplier delivery schedule

Available production time

Cycle time (machine, operators),

Setup time, uptime, OEE.

WIP (between processes)


Getting Ready Key Attributes:

Number of operators at each process,

Number of shifts

Inventory locations and quantities

Time between processes


Example Premiere Manufacturing Company

Processes:

Machining, deburring, crimping, testing, marking, shipping

Average demand: 10080 units per month=504 per day.

6720 per month #4 hoses=336 per day

3360 per month #6 hoses=168 per day

Shipping month: 20 days


Example Units/container: 24

Containers/day: 21

Supplier info: Company recieves a weekly shipment of 2500 units from its supplier ABC.


Example Process attributes

Shipping Frequency: daily

Finished goods inventory=2000 units

Marking Cycle time=50 sec

Changeover=5 min

Available time=27600 seconds

Uptime ratio=Availability=99%

1 operator


Example Process attributes

Marking

WIP=2000 units between testing and marking

Time between marking and shipping: 4 days

Similar data collected for Testing, Crimping, Deburring, Machining.


Example Flow of information and material

All communications with customer & supplier is electronic.

Prod. Control recieves monthly forecasts and weekly orders from customer.

Prod. Control transmits monthly forecasts and weekly orders to the supplier.

Weekly order release to production supervisor.


Example Flow of information and material

Daily order release to the processes.

All material pushed

FIFO lane between machining and deburring.


Mapping Current State 1. Draw icons for supplier, customer, production

control (STANDARD icons!).

2. Draw a data label below the customer icon. Enter customer req.s.

3. Enter shipping & receiving data:

Shipping icon below customer icon

Truck icons and delivery frequency

Direction arrows


Mapping Current State 4. Draw manufacturing processes boxes and label

them: Upstream: left, downstream: right.

Data boxes below each process icon.

Add a notched line (Turkish: entikli izgi) below the process boxes.


Mapping Current State 5. Enter process attributes into the data boxes for each

process. Show value-added time (cycle time) below each data box, on the notched line.

Write shift time, planned breaks, total available production time into the box, to upper right corner!


ABC Cord Inc.

MRP

Production

Control

6720 # 43360 # 6

Requirement=10080 /month

part

Weekly

Daily

Shipping

Machining Deburring Crimping

Testing

Marking

45 sec 5 sec 40 sec 30 sec 50 sec

x

x

U

ni

t

45CT= sec

60C/O= min

27600Avail= sec

87Uptime= %

5CT= sec

C/O= min

27600Avail= sec

100Uptime= %

40CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

30CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

50CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

Stats

LT= 34 days

TCT=170 sec

x

x

U

ni

t

x

x

U

ni

t

x

x

U

ni

t

xx Unit

1 shift/day= 8.5 hours

30 min unpaid lunch

Breaks= 20 min

Net Available Time= 460 min.

Per day

336 parts (# 4)

168 parts (#6)

504 parts Total

Steps 1-5:

21 Prepared by Dr. ule Itr Satolu

Attributes Defined Available production time= 460 min= 27600 sec.

Changeover times (C/O) per shift.

Changeover times, not planned downtime (Ex.:3600 sec for machining)

Uptime=Availability= Actual oper. time/Total Available Time

Uptime for machining= (27600-3600) / 27600 = 87%


Mapping Current State 6. Show information flow, both electronic and manual,

and their frequency.

Draw communication arrows from customer to production control,

Draw arrows from prod. control to supplier.

Draw arrow from prod. control to prod. Supervisor

Draw arrows from supervisor to the processes.


Daily

Daily

DailyDailyDaily

Weekly

Weekly orders

F/C MonthlyWeekly orders

F/C Monthly

ABC Cord Inc.

MRP

Production

Control

6720 # 43360 # 6


part

Weekly

Daily

Shipping


Testing

Marking


x

x

U

ni

t

45CT= sec

60C/O= min

27600Avail= sec

87Uptime= %

5CT= sec

C/O= min

27600Avail= sec

100Uptime= %

40CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

30CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

50CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

Stats

LT= 34 days

TCT=170 sec

x

x

U

ni

t

x

x

U

ni

t

x

x

U

ni

t

xx Unit


30 min unpaid lunch

Breaks= 20 min


Production

Supervisor

xx Unit

Per day

336 parts (# 4)

168 parts (#6)

504 parts Total

Step 6:

24 Prepared by Dr. ule Itr Satolu

Mapping Current State 7. Draw inventory icons at the places where

inventory is stored between processes, and

between the most upstream process and supplier,

between the most downstream process and shipping.

Calculate days of inventory (WIP) on hand and write the results on the time line.

Ex: 2000 hoses between testing & marking

2000 hoses / 504 hoses/day=3.96 days or 4 days


Daily

Daily

DailyDailyDaily

Weekly

Weekly orders


F/C Monthly

ABC Cord Inc.

MRP

Production

Control

6720 # 43360 # 6


part

Weekly

Daily

Shipping


Testing

Marking


10 days

45CT= sec

60C/O= min

27600Avail= sec

87Uptime= %

5CT= sec

C/O= min

27600Avail= sec

100Uptime= %

40CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

30CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

50CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

Stats

LT= 34 days

TCT=170 sec

7 days 4 days 4 days 4 days


30 min unpaid lunch

Breaks= 20 min


Production

Supervisor

2500

5 days

Per day

336 parts (# 4)

168 parts (#6)

504 parts Total

20003360 #4

1680 #63500 2000

2000


Mapping Current State 8. Draw in push, pull, FIFO locations.

Production based on a schedule: push!

Others: Combinations of pull or FIFO.



Daily

Daily

DailyDailyDaily

Weekly

Weekly orders


F/C Monthly

ABC Cord Inc.

MRP

Production

Control

6720 # 43360 # 6


part

Weekly

Daily

Shipping


Testing

Marking


10 days

45CT= sec

60C/O= min

27600Avail= sec

87Uptime= %

5CT= sec

C/O= min

27600Avail= sec

100Uptime= %

40CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

30CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

50CT= sec

5C/O= min

27600Avail= sec

99Uptime= %

Stats

LT= 34 days

TCT=170 sec

7 days 4 days 4 days 4 days


30 min unpaid lunch

Breaks= 20 min


Production

Supervisor

2500

5 days

Per day

336 parts (# 4)

168 parts (#6)

504 parts Total

20003360 #4

1680 #6

3500 2000

2000

Current State Map:

Points to Remember for Current State Mapping

Understand where you are now and decide where you want to go.

Focus on the most accurate information.

Gather actual info- not standard data.

Draw in pencil or on a white board: you will make several changes.


Lean Metrics Identify the metrics that will help you achieve your

goals. Inventory turns

Days of inventory on hand

WIP

Uptime

Lead time

On-time delivery

Total cycle time

Defective parts per million (PPM)


Lean Metrics Determine the current values (baseline) for the

identified metrics.

Metric Baseline

Total value stream WIP 17040 units

Total product cycle time 170 seconds

Total value stream lead

time

34 days

On-time delivery 88 %

Defective PPM-external 45

Uptime (=availability) 84 % Prepared by Dr. ule Itr Satolu 31

Lean Metrics Total value-stream lead time=34 days

But total value-added time=170 seconds.

Huge oppurtunity for improvement.

Percent of On-time delivery is 88% due to

Uptime issues in machining process

Shifting production schedules


Lean Metrics- Example Uptime = Availability=Actual operating time

Available production time

Actual operating time losses: Changeover time, quality problems, late delivery from

upstream, breakdowns, quality problems.

Improvement tech.: Setup time reduction (quick changeover techniques).

Track both internal & external defect rates.


Discussion to Identify Wastes 10 days of inventory between machining and

deburring- Why?

High changeover times- What is its impact on WIP?


Mapping the Future State Preparation:

Draw the customer, supplier, production control icons.

Add shipping data.


Mapping the Future State Stage-1: Focus on Demand

What is the demand? What is the takt time?

Can you meet takt time with current capabilities?

Need buffer stock, safety stock? How much?

Finished goods supermarket?

Other improvement tools?



1. Determine the takt-time and pitch for high volume products.

Takt-time = Available production time Required production quantity of the part family

Takt time= 27600 sec / 504 hoses

Takt time= 55 sec per hose

Pitch= Takt time * Pack-out Quantity

Pitch= 55 sec * 24 units/container

Pitch= 1320 sec= 22 min



2. Determine if you can meet demand with current capabilities.

Cycle time of line= 50 sec (longest cycle time)

Capacity= 27600 sec 50 sec/part= 552 parts

552 units*0.84=464 units (where uptime of the line=0.84)

464 < 504 units/day.

Actual capacity is less than required capacity.



3. Determine if you need buffer and safety inventories.

Buffer: when customer ordering pattern varies.

Safety: when internal constraints or inefficiencies disrupt flow.

Buffer & safety inventories are a hedge against uncertainty.



4. Determine if you need a finished goods supermarket

If you are 100% confident in the production system (flow), directly ship from the last process. Otherwise, a supermarket needed.

Maintain certain level of inventory by pull system!



5. Determine which improvement techniques to implement!

Quick changeover techniques (QCO):For machining.

Autonomous maintenance (to increase uptime)

5S for workplace organization and standardization.


Mapping the Future State Stage-2: Focus on Flow

Continuous flow:

Produce only those units needed

When they needed

In exact amounts

1. Perform line balancing: For evenly distributing work elements within a value stream to meet takt time!




Target

# of operators= 170 sec / 55 sec (takt time)= 3.09 operators

# of operators= 150 sec / 55 sec (takt time)= 2.7 operators

* Improve tooling

maintenance and

eliminate the need for

deburring.

* Distribute work of other

3 operations between the

operators.

* Reduce C/O times in

machining to 15 min.

* Achieve C/O time to


2. Plan for Work cells

Achieving a balanced line depends on applying principles of cell design.

Workers and machines for C,T,M grouped into a cell.

Workers can cooperate.



3. Determine how to control upstream production: At points where continuous flow is not achievable, determine how to control flow of prod.

Put supermarkets. Ex.: one between supplier-machining and the other machining-the cell.

Use a kanban system.

Use FIFO lanes.

Use computer assisted scheduling.



4. Determine which improvement methods to use

5S, TPM, autonomous maintenance and QCO in manufacturing cell. Why?

Standardized work, QCO, 5S at crimping-testing-marking cell.


Mapping the Future State Stage-3: Focus on Leveling

1. Decide on paced withdrawal or a Heijunka System, and Design or refine Kanban system.

2. Determine route of the material handler (runner). Map all material and information flow.

3. Determine which improvement methods to use.



It is necessary to create a Kanban system.

24 units per cont.

Containers reusable

Pitch=22 min.=55 sec X 24 units= 1320 sec



Withdrawal Kanban tells runner how many units to be pulled from finished goods supermarket.

Prod. Kanban tells the cell how many units should be replenished.

Signal Kanbans between machining and the cell tell the machining oper. How many units pulled from the supermarket.



Signal Kanbans at the upstream of machining tell supplier how much raw material pulled.

In the Heijunka box,withdrawal Kanbans are put and are visually controlled.



Future State Map

Takt=55 sec.

Buffer and safety stock in

shipping area.

Pitch=22 min.

U-shaped cell & std. Work

Heijunka & a runner.

Weekly orders


F/C Monthly

ABC Cord Inc.

Production

Control

Weekly

Daily

Shipping

Machining

Crimping/Testing/

Marking

45 sec 105 sec

2 days

45CT= sec

30C/O= min

27600Avail= sec

93Uptime= %

105CT= sec

< 1C/O= min

27600Avail= sec

100Uptime= %Stats

LT= 8 days

TCT=150 sec1 day


30 min unpaid lunch

Breaks= 20 min

Net Available Time= 460

min.

5 days

504 units/day

24 units/

container

Cell

TPM

5S

QCO

5S

Std. Work

VW

5S

55Takt= sec

Pitch=22

VW

S

B

S

1

QCO

5

4

W

2

P 3

Runner

S

Heijunka Box



(Tapping, Luyster, Shuker, 2002)

6 7 Value Stream Mapping

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