©2000 Washington State University 1
Transcript of ©2000 Washington State University 1
©2000 Washington State University 1
Washington State UniversityEngineering Management Programhttp://www.cea.wsu.edu/engrmgt/
James R. Holt, Ph.D., PE.Associate Professor of Engineering ManagementDr Holt’s Home Page: http://www.vancouver.wsu.edu/fac/holt/
EM 530 Applications in Constraints Management Session 5
Intro to Critical Chain Project Management Continued
The beginning of the solution
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Administrative• Communication:
– In-Class Phone (360) 546-9060– WebCT Communications
•Chat Room 1 monitored
• PowerPoint Slides for this presentation are also available at:
• http:///www.vancouver.wsu.edu/fac/holt/em530/
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The CCPM Solution to Project Management Scheduling
• Session 4 (Jun 5) was pretty depressing– Project Structure
– Task Variability
– Human Behavior (as a result of attempting to deal with structure and variability)
• Result, a single project planned for 70 days stretches to 160 days!
• Three 70 day projects exceed 350 days!
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Painful Situation
3 Projects
3 Projects
Normal Distribution, 50% Task Estimate Confidence
Skewed Distribution, 50% Task Estimate Confidence
Skewed Distribution, 60% Task Estimate Confidence
75% Task Estimate Confidence
85% Task Estimate Confidence
Add 75% Erroneous Reporting of Task Completions (Parkinson's Law)
Add Student Syndrome
90% Task Estimate Confidence
Add Multi-Project, Shared Resource (Queues)
Add Multi-Tasking
50 150 250 350 450100 200 300 4000
Statistical Summary for PmSim Project Management Simulation
R. Furbeck 3/28/99
6e
8a
6d
6c
6a
6b
5
8b
9a
9b
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We have Maxed Out!
• “We are caught in a vicious cycle which leads us to inflate our estimates and press for more people, just to see the completion dates of our projects slipping more and more into the future ...
• “... until the time to do the project becomes so long or the compromises on the content become so large that the clients tell us, “If that’s the case we’ll go elsewhere !” Eli Goldratt
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We must improve or lose business and people
• “At that Stage, a very unsatisfactory equilibrium is reached:
• Lead times are long
• Visibility is lost
• The work environment is chaotic
• There is a loss of ability to make decisions
• Everything is done by pressure.” Eli Goldratt
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Is it Possible?
• Some people have done it (See AGI Web)
• Example: Israeli Aircraft IndustriesF-16 Maintenance - Problem Resolution Flow
Time
0
20
40
60
80
100
120
140
160
1 2 3 4 5 6
Month
Le
ad
Tim
e (
da
ys)
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What are the elements of the Solution?
• It makes know sense to intentionally schedule conflict.
• Prioritize the work
• Stagger the release of work (Job Shop Game)
• Communicate what is important to those who can make a difference
• How?
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Multi Project Sim 9c
Tightest Scheduled Resource
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Basic Stagger
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Improvement helps a bitbut still Multi Tasking
First Project Median 169
Second Project Median 219(total time 323)
Third Project Median 235(total time 367)
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We can Prioritize and try to do one at a time!
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We are not good enough yet. We need protection
1 2 3 4 5 6 7 8 9 10
Completion Distribution
Due Date
Buffer
If we buffer our existing schedule,we just add more time!This is counter productive!
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Take advantage of good statistics
1 2 3 4 5 6 7 8 9 10
Completion Distribution
Due Date
Buffer
Before: 85% Estimate
Completion Distribution
Due Date
Buffer
After: 50% Estimate
1 2 3 4 5 6 7 8 9 10
Notice, we areonly changing the schedule.Actual work is the same. If we finish early, we can capturethe advantage.
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We can buffer the Critical Chain, but where else?
Completion Distribution
Due Date
Buffer
After: 50% Estimate
1 2 3 4 5 6
7 8 9 10
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Add Resource Buffers
Completion Distribution
Due Date
Buffer
After: 50% Estimate
1 2 3 4 5 6
7 8 9 10
Make sure Resources are available to work when needed on the CriticalChain
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Add Assembly (Feeder) Buffers
Completion Distribution
Due Date
Buffer
After: 50% Estimate
1 2 3 4 5 6
7 8 9
10 Make sure non-criticalside chains are de-coupledfrom the Critical Chain
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Single Project Buffered
Critical Chain
Avoid Conflict
Sim 8 Resource Buffers
Feeder Buffers
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Sim 8 Results
End of Buffer 98
Previous Median
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Now let’s look at Multi Project
• We Schedule Each Project according to Critical Chain Project Management
• We stagger the projects according to a selected strategic drum (resources)
• We include a buffer between projects (on the drum)
• Estimate at 50%, Use Buffer Management
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Stagger Projects w/Buffer
Buffer Between Projects Too
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Result with 50% schedule and Buffers
First Project Median 96 90%@110
Expected
Second Project Median 180 90%@210
Expected
Third Project Median 216 90%@245
Expected
3 P ro jects
3 P ro jects
N orm al D istribu tion , 50% Task E stim ate C onfidence
S kewed D istribu tion, 50% Task E stim ate C onfidence
S kewed D istribu tion, 60% Task E stim ate C onfidence
75% Task E stim ate C onfidence
85% Task E stim ate C onfidence
A dd 75% E rroneous R eporting o f Task C om ple tions (P arkinson 's Law)
A dd S tudent S yndrom e
90% Task E stim ate C onfidence
A dd M ulti-P ro ject, S hared R esource (Q ueues)
A dd M ulti-Tasking
P rio ritize P ro jects,S chedu le D rum
U se C ritica l C hain S chedu les and B uffer M anagem ent,R educe E rroneous R eporting o f Task C om ple tions to 50%
50 150 250 350 450100 200 300 4000
Statistical Summary for PmSim Project Management Simulation
R. Furbeck 5/11/00
6e
8a
6d
6c
6a
6b
5
8b
9a
9b
9c
9d
9e
E lim inate B ad M ulti-Tasking
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Bottom Line
• There is lots to gain
• Particularly in Multi Project Environments
• Single Projects 20% reduction
• Multi Projects 50% reduction
• Check out the simulators on your own.