Engineering-based processes and agile methodologies for software development: a comparative case study

The emergence of various software development methodologies raises the need to evaluate and compare their efficiencies. One way of performing such a comparison is to have different teams apply different process models in the implementation of multiple versions of common specifications. This study defines a new cognitive activity classification scheme which has been used to record the effort expended by six student teams producing parallel implementations of the same software requirements specifications. Three of the teams used a process based on the Unified Process for Education (UPEDU), a teaching-oriented process derived from the Rational Unified Process. The other three teams used a process built around the principles of the Extreme Programming (XP) methodology. Important variations in effort at the cognitive activity level between teams shows that the classification could scarcely be used without categorization at a higher level. However, the relative importance of a category of activities aimed at defining "active" behaviour was shown to be almost constant for all teams involved, possibly showing a fundamental behaviour pattern. As secondary observations, aggregate variations by process model tend to be small and limited to a few activities, and coding-related activities dominate the effort distribution for all the teams.