Value of Systems Engineering INCOSE Data

“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

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)

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.

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.

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