Lean Manufacturing
The 7 Value Stream Mapping
Tools & VALSTAT
The 7 Tools
• Centre around the “7 Wastes”.
• Well known tools
– 2 new ones
• No methodology to help choose most
appropriate.
Origins of the Mapping Tools
Mapping Tool
Origin of Mapping Tool
Process Activity Mapping
Industrial Engineering
Supply Chain Response
Matrix
Production Variety Funnel
Time compression/ logistics
Quality Filter Mapping
New Tool
Demand Amplification
Mapping
Decision Point Analysis
Systems Dynamics
Physical Structure Mapping
Operations Management
Efficient Consumer
response/logistics
New Tool
Process Activity Mapping
Process Activity Mapping -Key
KEY
Information
Flow
Value
Added
Non Value
Storage
Added
Non Value
Transportation
Added
Value
Operation
Added
Non Value
Delay
Added
Non Value
Inspection
Added
Process Activity Mapping -Key
1. Study of the flow of processes.
2. Identification of waste.
3. Consideration of whether process can be
arranged in more efficient sequence.
4. Consideration of better flow pattern – layout,
routes etc.
5. Consideration of whether everything that is
being done is necessary.
Supply Chain Response Matrix
Supply Chain Response Matrix
• Shows critical lead-time constraints for a process.
• Cumulative lead time in a distribution co.
• Horizontal axis shows lead time for product internally
& externally.
• Vertical axis shows average amount of standing
inventory at specific points in the supply chain.
• Inventory and lead-times can be individually targeted
for improvement.
Product Variety Funnel
Product Variety Funnel
• Illustrates how company/supply chain
operates.
• Complexity to be managed.
• Where to target inventory reduction.
• Making changes to processing of products.
• Gain overview of company/supply chain.
Quality Filter Mapping
Quality Filter Mapping
•
•
Identifies where quality problems are in supply
chain.
Three types of quality mapped:
1. Product Defect – Defective goods passed on to
customers.
2. Service Defects – Problems given to customer not
directly related to product themselves. i.e. delivery,
documentation.
Quality Filter Mapping
3. Internal Scrap – defects produced in company that
are caught by inspection.
•
Shows where defects occur, identifying problems,
inefficiencies and wasted effort.
Demand Amplification Mapping
Demand Amplification Mapping
• How demand changes along supply chain.
• Decisions and analysis can be carried out using this
info.
– Manage fluctuations
– Redesign value stream
– Reduce fluctuation.
Decision Point Analysis
Decision Point Analysis
• Decision point – point where actual demand
pull gives way to forecast driven push.
• Where products stop being made according to
actual demand and are made against forecast
only.
• This tool shows where this point is.
Decision Point Analysis
•
We need to know where this point is for two
reasons:
1. Knowing where this is, it is possible to assess
processes operating downstream and upstream
from this point. Making sure they are working to
the same push/pull philosophy.
2. Long-term, various scenarios to view operation
of the value stream if the point is moved can be
carried out.
Physical Structure
Physical Structure
• Shows supply chain a industry level.
• Understand how the industry operates.
• Brings attention to areas that may not receive
sufficient developmental attention.
Volume Structure
• Various tiers both in supplier and distribution
area, with assembler as middle point.
• Depicts number of organisations involved –
area of each part is proportional to how many
organisations are in it.
Cost Structure
• Similar to volume structure.
• Area of diagram is directly linked to value-adding
process (cost-adding process).
• Makes it possible to analyse value adding
required in final product as it’s sold.
VALSTAT Table
Process
Activity
Mapping
Supply Chain
Response Matrix
Overproduction
L
M
Waiting
H
H
Transport
H
Inappropriate
Processing
H
Unnecessary
Inventory
M
H
Unnecessary
Motion
H
L
Defects
L
Overall Structure
L
Production
Variety Funnel
Quality Filter
Mapping
Demand
Amplification
Mapping
Decision Point
Analysis
L
M
M
M
M
Physical
Structure
Mapping
Wastes
H = High correlation and usefulness
M = Medium correlation and usefulness
L = Low correaltion and usefulness
L
L
M
L
M
L
H
M
L
H
M
H
H
L
M
L
General Comments
• Data from all of the tools can be integrated.
• Different tools highlight differing issues.
• Therefore more accurate key priorities are highlighted
•
E.g. if supply chain response was used individually,
its supplier lead time would be identified. However,
when data from quality filter mapping is added, ontime delivery would be identified.
Theory of Constraints
•
Goldratt’s Theory of Constraints has been
seen as having a conflicting approach to lean.
Synergies Between TOC and Lean
• TOC identifies potential improvements that
will make a big difference.
• TOC identifies the constraints that Lean can
then target for waste reduction – provides
focus.
Synergies Between TOC and Lean
• Lean has useful tools and philosophy and its
techniques enable understanding of the system
and its dependencies clearly.
• TOC helps to identify and quantify the
opportunities for improvement.
• Both encourage pull rather than push.