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Seven Steps to Creating a Value Stream Map (VSM)
Process Steps & Case Study
Revision: New
Date: Jan. 2014
Content:
Purpose
Process Steps
Case Study
Purpose:
This presentation identifies the steps needed to create a Value Stream Map VSM.
An example is provided using a case study that allows the user to witness the development of a VSM.
Process Step Approach
2. Draw Process Steps
3. Enter Process Data
4. Enter Inventory Count
5. Draw Material Flow : Supplier to Manufacturer, Manufacturer to Customer
6. Draw Information Flow and internal material flow
7. Calculate Lead Time, processing time & max value add %
1. Identify Customer Requirements
Step 1 : Identify Customer Requirements Customer Demand
Number of Shifts
Pack Size
Step 2 : Draw Process Steps For ease, combine parallel process steps
Step 3 : Enter Process Data Cycle Time
Changeover Time
Uptime
Amount of Operators
Seven Steps to Creating a VSM
Seven Steps to Creating a VSM
Step 4 : Enter Inventory Count Enter inventory count between each process step
Don't forget inventory at the beginning before 1st process step
Step 5 : Draw Material Flow From supplier
To customer
Step 6 : Draw information & internal material flow From Aircraft Assembly Plant to supplier
From production planning to process steps
Seven Steps to Creating a VSM
Step 7 : Calculate lead time, processing time & maximum value add %
Processing Time Sum of all cycle times
Lead Time Processing time + sum of all inventory times
Inventory time = inventory quantity/daily customer demand
For example, if the customer requires 20 items per day and there are 40 items in inventory. There is 2 days inventory time (waiting time)
Convert inventory time from days to minutes (include breaks, but not uptime or changeover time)
Maximum Value Add %
Max. Value add % = (processing time/lead time) x 100
Seven Steps to Creating a VSM
Introduction The Joe Bloggs Stamping Company produces several components for Aircraft Part
Assembly Plants
This case concerns one product family ; a Titanium Bracket Sub-Assembly in two types A1 and A2
These components are sent to Assembly Plant
Customer Requirements 320 pieces per month
200 per month Type A1
120 per month Type A2
Customer Plant operates 2 shifts
Palletised returnable tray packaging with 1 bracket per tray and up to 10 trays per pallet. The Customer orders in multiples of trays
Ships once daily to the Assembly Plant by road
Case Study: Joe Bloggs Stamping Company
Seven Steps to Creating a VSM
Work Time 20 days in a month
2 shift operation in all production departments
8 hours every shift, with overtime if necessary
Two 10 minute planned breaks during each shift
Manual processes stop during breaks
Unpaid lunch, all processes continue
Production Processes Joe Bloggs process for this product family involves stamping a metal part followed by
welding and subsequent assembly. The components are then stored and driven to the AssyPlant on a daily basis.
Switching between Type A1 and A2 brackets requires a 1 hour changeover in stamping and a 10 minute fixture change in the welding processes.
Coils (500m) are supplied by Coils R Us
Deliveries are made to Joe Bloggs on Tuesdays and Thursdays by truck.
Case Study: Joe Bloggs Stamping Company
Seven Steps to Creating a VSM
Case Study: Joe Bloggs Stamping Company
Joe Bloggs Production Control Department Receives Assy Plants 90/60/30 day forecasts and enter them into MRP via
Electronic Data Interchange (EDI)
Issues Joe Bloggs 6 week forecast to Coils R Us via EDI
Secures coil steel by weekly faxed order release to Coils R Us
Receives daily firm order from Assy Plant via EDI
Generates MRP (manufacturing resource planning) based weekly departmental requirements based on customer order, Work in Process (WIP) inventory levels, Finished Goods (F/G) inventory levels, anticipated scrap and downtime.
Issues requirements to Coils R Us for 500m coils
Issues weekly build schedules to Stamping, Welding and Assembly processes
Issues daily shipping schedule to Shipping Department
Seven Steps to Creating a VSM
Case Study: Joe Bloggs Stamping Company
All production processes occur in the following order, each piece goes through all process
1. Stamping(The press makes parts for many products)
1 Operator to run press
Automated 10 ton press with coil (automated material feed)
Cycle Time : 1 minute (60 pieces an hour)
Changeover Time : 1 Hour (good piece to good piece)
Machine Reliability : 85%
Observed Inventory
4000m of coils before stamping (enough to make 80 brackets)
150 pieces of Type A1 finished stampings
24 pieces of Type A2 finished stampings
Seven Steps to Creating a VSM
Case Study: Joe Bloggs Stamping Company
2. Spotweld Workstation 1(dedicated to this product family)
Manual process with 1 operator Cycle Time : 39 minutes
Changeover Time : 10 minutes (fixture change)
Reliability : 100%
Observed Inventory
36 pieces of Type A1 & 6 pieces of Type A2 after process
3. Spotweld Workstation 2(dedicated to this product family)
Manual process with 1 operator
Cycle Time : 46 minutes
Changeover Time : 10 minutes (fixture change)
Reliability : 80%
Observed Inventory
6 pieces of Type A1 before Spotweld 2
16 pieces of Type A1 & 18 pieces of Type A2 after Spotweld
Seven Steps to Creating a VSM
Case Study: Joe Bloggs Stamping Company
4. Assembly Workstation 1(dedicated to this product family) Manual process with 1 operator Cycle Time : 62 minutes Changeover Time : none Reliability : 100% Observed Inventory after process step
42 pieces of Type A1 & 6 pieces of Type A2
5. Assembly Workstation 2(dedicated to this product family) Manual process with 1 operator Cycle Time : 40 minutes Changeover Time : none Reliability : 100% Observed finished goods inventory in warehouse
27 pieces of Type A1 & 14 pieces of Type A2
6. Shipping DepartmentRemove parts from finished goods warehouse and prepares them for shipment to the customer
Seven Steps to Creating a VSM
Mon.
+ Wed.
FIFO
Assembly
XYZ
Corporation
C/T = 45 sec
C/O = 30 min
3 Shifts
2% Scrap
Manufacturing
Process
Outside
Sources
Data BoxI
300 pieces
1 day
Inventory
Truck
Shipment
PUSH
Arrow
Finished Goods
to Customer
First-In-First-Out
Sequence Flow
Supermarket
Withdrawal
Material Flow Icons
Seven Steps to Creating a VSM
Weekly
ScheduleOXOX
Manual
Information Flow
Electronic
Information Flow
Schedule Load Levelling
Withdrawl
Kanban
Production
Kanban
Signal Kanban
Kanban Post
Sequenced-Pull Ball
Go See Scheduling
Kanban Arriving
in Batches
Information Flow Icons
Seven Steps to Creating a VSM
Improvement Lightening
Burst
Buffer or Safety Stock
Operator
General Icons
Seven Steps to Creating a VSM
C/T = 1 Min
C/O = 1 Hour
Uptime = 85%
1 x
10T
Stamping
C/T = 39 Min
C/O = 10 Min
Uptime = 100%
1 x
Spot Weld 1
C/T = 46 Min
C/O = 10 Min
Uptime = 80%
1 x
Spot Weld 2
C/T = 62 Min
C/O = 0
Uptime = 100%
1 x
Assembly 1
C/T = 40 Mins
C/O = 0
Uptime = 100%
1 x
Assembly 2 Shipping
320 Pieces/Month
200 A1
120 A2
2 Shifts
Pack Size 1
Aircraft Assembly
Plant
I
27A1
14A2
I
42A1
6A2
I
16A1
18A2
I
42A1
6A2
I
150 A1
24A2
I
80
Identify Customer Requirements, Draw Process Steps, Enter Process Data and Enter Inventory Count
Case Study: Steps 1-4
Seven Steps to Creating a VSM
C/T = 1 Min
C/O = 1 Hour
Uptime = 85%
1 x
10T
Stamping
C/T = 39 Min
C/O = 10 Min
Uptime = 100%
1 x
Spot Weld 1
C/T = 46 Min
C/O = 10 Min
Uptime = 80%
1 x
Spot Weld 2
C/T = 62 Min
C/O = 0
Uptime = 100%
1 x
Assembly 1
C/T = 40 Mins
C/O = 0
Uptime = 100%
1 x
Assembly 2 Shipping
320 Pieces/Month
200 A1
120 A2
2 Shifts
Pack Size 1
Aircraft Assembly
Plant
I
27A1
14A2
I
42A1
6A2
I
16A1
18A2
I
42A1
6A2
I
150 A1
24A2
I
80
1 x Daily
Tues &
Thurs
Coils R Us
500M Coils
Draw Material Flow : Supplier to Manufacturer and Manufacturer to Customer
Case Study: Step 5
Seven Steps to Creating a VSM
C/T = 1 Min
C/O = 1 Hour
Uptime = 85%
1 x
10T
Stamping
C/T = 39 Min
C/O = 10 Min
Uptime = 100%
1 x
Spot Weld 1
C/T = 46 Min
C/O = 10 Min
Uptime = 80%
1 x
Spot Weld 2
C/T = 62 Min
C/O = 0
Uptime = 100%
1 x
Assembly 1
C/T = 40 Mins
C/O = 0
Uptime = 100%
1 x
Assembly 2 Shipping
320 Pieces/Month
200 A1
120 A2
2 Shifts
Pack Size 1
Aircraft Assembly
Plant
I
27A1
14A2
I
42A1
6A2
I
16A1
18A2
I
42A1
6A2
I
150 A1
24A2
I
80
1 x Daily
Tues &
Thurs
Coils R Us
500M Coils
MRP
Production Planning
Daily Expedite
6 Week Forecast
Weekly Fax
30/60/90 Day F/C
Weekly Plan
Daily
Shipping
Plan
Draw Information Flow and Internal Material Flow
Case Study: Step 6
Seven Steps to Creating a VSM
C/T = 1 Min
C/O = 1 Hour
Uptime = 85%
1 x
10T
Stamping
C/T = 39 Min
C/O = 10 Min
Uptime = 100%
1 x
Spot Weld 1
C/T = 46 Min
C/O = 10 Min
Uptime = 80%
1 x
Spot Weld 2
C/T = 62 Min
C/O = 0
Uptime = 100%
1 x
Assembly 1
C/T = 40 Mins
C/O = 0
Uptime = 100%
1 x
Assembly 2 Shipping
320 Pieces/Month
200 A1
120 A2
2 Shifts
Pack Size 1
Aircraft Assembly
Plant
I
27A1
14A2
I
42A1
6A2
I
16A1
18A2
I
42A1
6A2
I
150 A1
24A2
I
80
1 x Daily
Tues &
Thurs
Coils R Us
500M Coils
MRP
Production Planning
Daily Expedite
6 Week Forecast
Weekly Fax
30/60/90 Day F/C
Weekly Plan
Daily
Shipping
Plan
4600
Mins
1 Min
2392
Mins
2760
Mins
1932
Mins
2760
Mins
10,028
Mins
40 Mins62 Mins46 Mins39 Mins Processing Time =
188 Mins
Production Lead
Time = 26.8 Days
Case Study: Step 7
Calculate Lead Time and Processing Time
Seven Steps to Creating a VSM
1 Working Day8 Hours x 2 Shifts
8 x 60 x 2 = 960 Minutes
960 Minutes Breaks
960 40 = 920 Minutes
Convert Lead Time to MinutesLead Time = 26.8 Days
26.8 x 920 = 24,660 Minutes
Calculate Max. VA %Max VA% = (processing time / lead time) x 100
= (188 / 24660) x 100
= 0.76%
Therefore the Max VA% indicates that the item has only been worked on for 0.76% of the time it has been within the value stream (touch time)
The 0.76% is not all value add time because some of the cycle time within the process steps could be waste
This is why it is called Maximum Value Add %, because even with a perfect process (with no waste) the Max VA % could only ever be 0.76%
Case Study: Step 7 Max Value Add %