1. 1 Systems Engineering Reuse Principles Jared Fortune, USC Ricardo Valerdi, MIT COSYSMO Workshop @ COCOMO Forum 2010 Los Angeles, CA

2. Need to Estimate Effect of Systems Engineering Reuse Practitioners noted large errors between model estimates and actuals –Variations discovered to be attributable to programs with reuse Systems engineering reuse –The utilization of systems engineering products from previous efforts –Ex: architectures, requirements, test plans, interfaces –Means of reducing cost, schedule, and/or risk Current version of the model assumes all systems engineering products will be “built from scratch” –Unable to account for the impact of systems engineering reuse …COSYSMO 2.0 2

3. COSYSMO 2.0 Operational Concept 3

4. Model Form 4 Where: PM NS = effort in Person Months (Nominal Schedule) A = calibration constant derived from historical project data w r = weight for reuse category r = {New, Designed for Reuse, Modified, Deleted, Adopted, Managed} w x,k = weight for size driver x = {Easy, Nominal, Difficult} k = {Requirements, Interfaces, Algorithms, Scenarios} Φ = quantity of “k” size driver E = represents (dis)economies of scale EM = effort multiplier for the j th cost driver

5. Reuse Categories CategorySub-CategoryDefinition I) NewProducts that are completely new i) Designed for Reuse Products that require an additional upfront investment to improve the potential reusability II) ModifiedProducts that are inherited, but are tailored ii) DeletedProducts that are removed from the system III) AdoptedProducts that are incorporated unmodified (a.k.a. “black box” reuse) iii) ManagedProducts that are incorporated unmodified and with minimal testing 5

6. Reuse Category Weights 6

7. COSYSMO 2.0 Implementation Results Across 44 projects at 1 diversified organization Using COSYSMO: –PRED(.30) = 14% –PRED(.40) = 20% –PRED(.50) = 20% –R 2 = 0.50 Using COSYSMO 2.0: –PRED(.30) = 34% –PRED(.40) = 50% –PRED(.50) = 57% –R 2 = 0.72 Result: 36 of 44 (82%) estimates improved September 10, 20097

8. Reuse Framework 8

9. 9 Academic COSYSMO 2.0 (without reuse)

10. September 10, 200910 Academic COSYSMO 2.0 (with reuse)