1. Value of Systems Engineering INCOSE Data

2. “System Thinking” Design
Heuristic Claim of SE
Better systems engineering leads to
Better system quality/value
Lower cost
Shorter schedule
SYSTEM
DESIGN
DETAIL
PRODUCTION
INTEGRATION
TEST
Traditional Design
Time
Risk
Saved
Time/
Cost
“System Thinking” Design
Time
Risk

3. NASA Tracking 1980s % Investment in System Engineering Effort (SEE)
Total Program Overrun
32 NASA Programs
In the late 1980s, Werner Gruhl of the NASA Comptroller’s office set out to improve cost estimation on NASA projects. As part of his effort, he mandated that NASA projects track costs to a common Work Breakdown Structure (WBS) that would allow gathering data across projects. This additional tracking was funded as part of each project. Over several years of live and historic projects, he developed the chart shown above that shows the impact of front-end investment (i.e. system definition and analysis) on the accuracy of cost estimation.
% Investment in
System Engineering Effort (SEE)

4. Time-Phased Sensitivity of SE to Total System Life Cycle Cost%
Commitment to Technology,
Configuration, Performance, Cost, etc.
100 75
Cost Incurred 50
System-Specific Knowledge 25
Ease of Change N E D
Conceptual-
Preliminary
Design
Detail
Design and
Development
Construction
And/or
Production
System Use,
Phase out, and Disposal
Commitment, System-Specific Knowledge, and Cost
Systems Engineering is important early in a program to influence the design when incurred costs are low and design changes are easy.

5. Concept and Technology Development
Preliminary
System Design
Phase
Conceptual System
Design Phase
Detail Design and Development
Phase
Systems Engineering
High
Individual Design Disciplines
Design Influence
As system design and development progresses during system development, the flexibility to implement system design changes is reduced and the cost impact of introducing changes is increased. Systems engineering has its greatest opportunity to influence design decisions earlier in systems design and development when the system design is still in evolution.
Low
Systems Design and Development Progress
Systems Engineering is important early in a program to influence the design when incurred costs are low and design changes are easy.

6. Conclusions SE effort improves development quality
Cost, schedule, subjective
Hypothesis is supported by the data
Optimum SE effort is 10-15%
Matches data from NASA projects
Cost, schedule overruns are minimized
However, note wide dispersion of data
Quality of the SE effort matters
Lower quality SE reduces effectiveness