Toward A Framework for Implementing Systems
Engineering Development for Complex Systems
Karl L. Brunson, GWU
Thomas A. Mazzuchi, D.Sc., GWU
Shahram Sarhani, Ph.D., GWU
Jeffrey Beach, D.Sc., GWU
Outline
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What is the purpose
Development of ICM Framework
Life-cycle Risks
Acquisition Life-cycle
Complex System Work Breakdown Structure
Framework Schedule Development
Risk Assessment of Complex System
2
Purpose
Framework
Risks
What is the Purpose?
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Provide a Comprehensive and Flexible Systems
Engineering Development Framework for Complex Systems
 Builds on the strengths and principles of proven process
models such as1:
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Life-cycle
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WBS
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Framework
Schedule
Applies key principles that are used throughout an
acquisition life-cycle1:
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Risk
Assessment
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1.
Waterfall, V
Iterative
Spiral Development
Agile
Rapid Unified Process
Performs risk driven process tailoring throughout life-cycle phases
Incremental Commitment Model
Boehm, Barry and Lane, Jo Ann, Using the Incremental Commitment Model
to Integrate System Acquisition, Systems Engineering and Software Engineering, USC, CSSE
3
Purpose
Goal to achieve with the Framework
Framework
Risks
Waterfall
Iterative
Life-cycle
WBS
Spiral
Development
Complex System
Framework
Schedule
Risk
Assessment
Incremental Commitment Model
4
Purpose
Framework
Risks
Schedule and Cost Risks
Minimization of Schedule Risks
• Product of Probability of certain project durations
• Understand the risk drivers, likelihood and consequence
Life-cycle
WBS
Framework
Schedule
Risk
Assessment
Minimization of Cost Risks
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•
•
•
•
Activity duration
System complexity
Sizing and Technology
System Capability
Stakeholder oversight
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Purpose
Life-Cycle Phases and Activities
Framework
Identify the
acquisition
life-cycle:
Risks
Verification & Validation Loop
Life-cycle
WBS
Preliminary & Detail Design Loop
Design
Synthesis
Requirement Loop
Risk
Requirement
Assessment s Analysis
Concept Design Loop
Phase A
Preliminary
Analysis
Phase B
Definition
• Department of
Defense
• NASA
Outline phase
content:
Functional
Analysis
Framework
Schedule
Advanced
Studies
Pre-Phase A
Engineering
V&V
• Tasks
• Activities
Phase C
Design
Phase D
Development
Phase E
Operation
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Purpose
Framework
Define Work Breakdown Structure of
Complex System
Level 1
Satellite
Risks
Life-cycle
Level 2
Bus
Payload
WBS
Framework
Schedule
Level 3
Attitude
Control
Structure
Internal
Instruments
Risk
Assessment
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Purpose
Framework
Risks
Life-cycle
WBS
Framework
Schedule
Develop Baseline Schedule
for Complex System
ID
1
Name
Start Milestone
Duration 3rd Quarter 4th Quarter 1st Quarter
10/4
0d
2
Payload
125 d
50 d
75 d
125 d
50 d
70 d
0d
3
Design Component A
4
Develop Component A
5
Bus
6
Design Component B
7
Develop Component B
8
Finish Milestone
10/3
11/22
11/23
10/3
2/5
11/23
11/28
2/5
2/5
Risk
Assessment
8
Purpose
Develop Schedule for each Framework
Framework
Waterfall
Risks
Life-cycle
Iterative
WBS
Framework
Schedule
Spiral
Development
Risk
Assessment
ICM
9
Purpose
Framework
Risks
Life-cycle
Map Risk Drivers to Schedule Tasks
Risk ID Risk Driver
001 Design issues
Framework
Schedule
1
002 Resource Availability
003 Resource Complexity
2
004
4
005
006
WBS
Task ID
007
008
Requirement Creep
Late Deliveries
Duration Underestimation
Task Definition Changes
Budget Changes
Waterfall
3
Iterative
5
6
7
8
Spiral
Development
Risk
Assessment
ICM
• Risk drivers can be mapped to more than one task
• Risk assessments will be translated with triangular
probability distributions for consequence/impact
and with binomial distributions for the likelihood
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Purpose
Framework
Risks
Life-cycle
Model Schedule Behavior with Risk Drivers
Risk ID Risk Driver
001 Design issues
2
004
4
005
007
008
Framework
Schedule
Risk
Assessment
Requirement Creep
Late Deliveries
Duration Underestimation
Task Definition Changes
Budget Changes
Waterfall
1
002 Resource Availability
003 Resource Complexity
006
WBS
Task ID
Iterative
3
5
Spiral
Development
6
7
ICM
8
• Run Monte Carlo Simulations for each framework
• Outputs produce probability density distributions and
binomial distributions that associates risk drivers to tasks
via likelihood and consequence
• Indentifies critical path of each framework
• Quantifies the impacts and consequence of risk drivers
• Risk dependencies modeled via correlation
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Purpose
Risk Assessment of Complex System
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Framework
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Risks
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Life-cycle
Cumulative distributions for schedule and costs
Impact of risks on specific tasks
Probabilistic critical paths for each framework
identify tasks/activities that will most likely delay
project
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WBS
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Framework
Schedule
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Risk
Assessment
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Depends on risk
Monte Carlo shows whether task was critical per iteration
Correlation between tasks when risk driver
affects durations
Task durations can be negatively or positively correlated
Framework selection based upon results of schedule and cost
risk analysis of probability distributions
Reveals optimal paths to risk reduction
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