COSYSMO Reuse Extension COSYSMO Workshop – USC CSSE Annual Research Review March 17, 2008 Ricardo ValerdiGan Wang Garry RoedlerJohn Rieff Jared Fortune

2 Overview Background COSYSMO currently assumes all system components are new –…but most systems are not entirely new, have a significant amount of reuse Current goal is to develop an approach for handling reuse –Organizations can adapt to their own business model Objectives Provide an overview of research –Proposed terminology –Possible methodology Identify next steps

3 Background on Software Reuse Main size driver = KSLOC Adapted Source Lines of Code (ASLOC) Percent of Design Modification (DM) Percent of Code Modification (CM) Percent of Integration Required for Modified Software (IM) Percentage of reuse effort due to Software Understanding (SU) Percentage of reuse effort due to Assessment and Assimilation (AA) Programmer Unfamiliarity with Software (UNFM) From COCOMO II Model Definition Manual (p. 7-11) AAF

4 Proposed Reuse Terminology New: –Items that are completely new, generally unprecedented and with low level of familiarity Modified: –Items that are inherited, but require a limited amount of tailoring to be incorporated Adopted: –Items that are incorporated unmodified, “black-box” reuse Deleted: –Items that are removed from a system (in legacy but not current system) Managed: –Items incorporated unmodified and untested (subcontractor effort)

5 Reuse Continuum Modified Adopted New Deleted Managed Reuse weight

6 Approaches for Handling Reuse in COSYSMO Calculate equivalent requirements weights for size drivers Reuse Capture reuse-class cost parameters for different classes of reuse Activity-based/Bottoms up (requires effort data by activity) Solve for the weights (requires data from projects)

7 Step 1:Define the discriminating, lifecycle systems engineering activities. Correlate defined activities with EIA-632 defined tasks to ensure that there is no obvious gaps. Step 2:Define the levels of reuse based on the lifecycle SE activities (without adjectives) Step 3:Evaluate % systems engineering effort for each level of reuse in terms of EIA- 632 process groups and ISO life cycle to derive the weights of reuse Bottoms-Up Activity-Based

8 Activity-based/Bottoms up

9 Next Steps Reach conclusion on reuse weights –Thoughts on bottoms up calculations vs. solving for weights? Determine scalability of reuse –How to deal with commonalities across multiple projects/organizations? Examine effect of SE “designed” for reuse –What are the penalty/savings? Where do they occur in lifecycle? Apply methodology –Who else has reuse data?

10 Author Contact Information Ricardo Valerdi, MIT Gan Wang, BAE Systems Garry Roedler, Lockheed Martin John Rieff, Raytheon Jared Fortune, USC