Lean Aerospace Initiative
Plenary Workshop
Cycle Time Reduction with Part
Synchronization
March 31- April 1, 1998
Presented By:
Tom Shields
MIT
Research Sponsored By LAI
Lean Aerospace
Initiative
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Outline
Context
Design and management of
complex manufacturing
systems
Engine sector research
Engine Study results
System characteristics
Observations
FO Shields 033198-2 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
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Achieving Lean:
Some Accepted Wisdom
Customer satisfaction
– Produce to actual demand
– Provide predictable output & rapid
response to undesired events
– Desired quality
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Continuous Improvement
– Systemic
– Iterative
FO Shields 033198-3 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
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Customer Satisfaction
Produce to actual demand
– On time delivery
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Provide predictable output & rapid
response to undesired events
– Low variability in throughput time
– Ability to recover schedule
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Desired quality
– Fitness to standard
– Fitness to use
– Fitness to cost
FO Shields 033198-4 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
Continuous Improvement
Continuous =
Systemic
Iterative
+
Improvement
Improvement
Improvement
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Aspects
– Action based on facts/data
– Focus on the vital few
FO Shields 033198-5 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
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Key Aspects of Continuous
Improvement
Action based on facts
– Understanding of the process
– Example: Flow chart
– Use data as the basis for decision making
– Example: Check sheet (how often do certain events happen)
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Focus on the vital few
– Identify causes
– Address the biggest problem first
FO Shields 033198-6 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
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Research Project: Design &
Management of Complex Systems
Key Questions
– What enables flow optimization to reduce cycle time?
– What are other manufacturing system elements that
enable this reduced cycle time?
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Method
– Investigate similar products in each sector
– Focus on assembly operations
– Measure key performance metrics
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Progress
– Engine sector completed
– Airframe sector under study
FO Shields 033198-7 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
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Engine Sector Research
Three sites
Studied final assembly of engines
Research focus
– Build times
– Sources of delay
– Delivery history
– Manufacturing system performance
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Subsequent investigation of supplier
network
FO Shields 033198-8 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
Engine Sector Study Results
Customer Satisfaction = On Time Delivery
Site
A
B
C
Delivery history
Late
On Time
35%
65%
30%
70%
0%
100%
FO Shields 033198-9 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
18.0
Part Count
16.0
Normalized Build Time
(actual/planned build time)
Engine Sector Study Results
(Con’t)
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14.0
12.0
Average Build Time
Shortest Build Time
10.0
Longest Build Time
8.0
6.0
Key attributes
of superior
performance:
– Build on time
– Predictable
build time
4.0
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B1
B2
A1
A2
C2
C1
Site Engine Lines
FO Shields 033198-10 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
Nonattributable
Parts shortage
Quality
Resources
Sources of Build Delay
A1
47%
38%
13%
2%
B2
70%
16%
14%
C
3%
97%
0%
• Sites A & B did not track build time or
sources of delay
• Site C did track build time and other data
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Based on weekly measurements of delay sources
2 Based on perceptions from multiple levels
FO Shields 033198-11 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
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What Will Improve the Part
Shortage Problem?
Part synchronization to assembly ops
– Don’t start until all parts available
– Ensure all parts are available when needed
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Systemic factors
– Planning
– Scheduling
– Supplier networks
– Long term agreements
– Certified suppliers
FO Shields 033198-12 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
Key:
Part Synchronization
Supplier
Assembly
Plant
Warehouse
MRP
MRP
Kanban
80% of
parts value
Monthly
Batches
MRP
A - Push
Kanban
B - Push
C - 80% Pull
FO Shields 033198-13 ©1998 Massachusetts Institute of Technology
Lean Aerospace
Initiative
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Observations
Systemic attack on part synchronization
yields major benefits to on time build
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Must have information to focus actions
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Cycle time continues to be important metric
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Production synchronization with suppliers
requires steps beyond long term
agreements and certified suppliers
FO Shields 033198-14 ©1998 Massachusetts Institute of Technology