The Information Gathering Strategies of Software Maintainers Carolyn B. Seaman UMBC, Baltimore, USA and Fraunhofer Center – Maryland

Research Strategy Problem: Maintainers spend a lot of time collecting and digesting information about systems being maintained Solution strategy: –Find out what information sources maintainers rely on –Determine which sources are most effective –Apply results in practice

Related Work Lientz and Swanson 1978 –“50-85%” Singer 1998 –field survey of maintenance practice – “Source code is king” Briand et al 1998 –qualitative methods and organizational modeling Sousa and Moreira 1998 –survey of Portuguese financial software developers Tjortjis and Layzell 2001 –qualitative study of learning strategies

Study Design Survey –Background questions –Rate a list of information sources on usefulness, convenience, frequency of use, and availability –Top 3 and bottom 3 –Wish List Distribution –Rigorous review –Pilots in each organization –Post interviews in one organization Quantitative and qualitative analysis of survey responses

Respondents CSC N = 38 From unit working on space science applications Highly experienced 1/3 were involved in the original release Age of systems varied, most >5 years old Unix/C/C++ (50%) and mainframe/Fortran (25%) IRS N = 7 From several units, working on tax enforcement systems Even more experienced Very few were involved in the original release Age of systems varied, most <5 years old Mainframe/COBOL

Results CSC Source code highest rated All types of people more useful than other sources Original developers highly sought after but largely unavailable Current users useful and available, but not consulted frequently Colleagues useful and available but not often consulted; those without them wished for them IRS Source code highest rated Few knowledgeable people available, but not desired Original developers were available, but not very useful due to system change Current users useful and available, and consulted frequently Colleagues useful when available, but not desired

Results (cont.) CSC CASE tools largely unavailable but not desired Available tools not rated high Lukewarm on both system documentation and CM Lessons learned not convenient or frequently used when available; not desired when not available IRS CASE tools largely unavailable but desired Available tools not rated high Heavy reliance on system documentation within CM Lessons learned highly useful when available; highly desired when not available

Conclusions “Somebody to talk to and something to help me understand the code.” … But which is more important? Maintainers rely on people - but who depends on the situation Maintainers need tools - but not fancy ones