1 Discussion on Reuse Framework Jared Fortune, USC Ricardo Valerdi, MIT COSYSMO COCOMO Forum 2008 Los Angeles, CA

2 Operational Concept COSYSMO 2.0 Size Drivers Effort Multipliers Effort Calibration # Requirements # Interfaces # Scenarios # Algorithms + 2 Volatility Factors - Application factors - 9 factors - Team factors - 7 factors - Schedule driver

3 COSYSMO 2.0 Model Where: r = {New, Modified, Adopted, Deleted, Managed} w r = weight for defined degrees of reuse Goals Capture technical and non-technical effects of reuse Introduce minimal modifications to the original model Keep new drivers independent from existing drivers

4 Proposed Size Driver Extensions New: Artifacts that are completely new Modified: Artifacts that are inherited, but are tailored Adopted: Artifacts that are incorporated unmodified, also known as “black box” reuse Deleted: Artifacts that are removed from a system Managed: Artifacts that are incorporated unmodified and untested

5 Size Driver Extensions Specific General

6 Reuse Understanding

7 Reuse Understanding – Rating Scale

8 Artifact Unfamiliarity

9 Artifact Unfamiliarity – Rating Scale

10 Proposed COSYSMO 2.0 Methodology Capture the effect of reuse in both the size and cost drivers –Does this make sense? Reuse extensions for the size drivers has already been proposed Are the two COSYSMO 2.0 cost drivers sufficient? –Adequately capture the effects of reuse outside the size drivers?

11 Implementation Reuse size driver extensions and more cost drivers sounds good from an academic perspective …but this is a slippery slope –5 reuse categories = 60 systems engineering size values –20 model parameters = ~100 calibration projects Just for reuse! What about: –Operations, maintenance, disposal –Risk –Schedule …and all the rest

12 Questions Do we really need 5 reuse categories? –Do we have the correct definitions? –Is this supportable? How many is too many drivers in the model? –Reuse requires 1-2 cost drivers to complement reuse extensions –Should we explore a subset of the model to provide a “good enough” estimate? –Opportunity to balance adding more parameters with capability to produce an estimate with fewer parameters Other thoughts? Deficiencies?

13 Next Steps Conduct Delphi survey on COSYSMO 2.0 drivers –Weights for reuse extension and two additional drivers Begin data collection process –Want to “reuse” as many projects from COSYSMO data set as possible that involved systems engineering reuse –Collection of additional projects will also help to improve the COSYSMO model Plan to provide preliminary results of COSYSMO 2.0 at CSSE Annual Research Review (March 2009)