A Descriptive Model of Software Development to Guide Process Improvement

Software process improvement can follow a capability maturity model such as SPICE or CMMi. Or it can focus on improving selected software processes in detail. The latter can either be a stand-alone improvement activity, or it can tune processes that were established or modified due to a large-scale assessment. Some software processes need to be adjusted qualitatively: process steps or deliverables need to be added, modified, or dropped from the process. In many cases, however, the complexity of software processes comes with their quantitative aspects: while testing is a good activity, for example, it must neither be carried out too long nor too short. Quantitative analysis of software processes requires an adequate model to capture relevant aspects. This paper presents a descriptive approach to model software development. It covers effort, size of deliverable, and quality, and it helps to better understand effects occurring in software projects. Key concepts and modeling examples are presented. Our FLOW project investigates opportunities to improve software processes based on optimizing project information and experience flows. A descriptive model of software project dynamics is an important ingredient.