Adapting the "Staged Model for Software Evolution" to Free/Libre/Open Source Software

Research into traditional software evolution has been tackled from two broad perspectives: that focused on the how, which looks at the processes, methods and techniques to implement and evolve software; and that focused on the what/why perspective, aiming at achieving an understanding of the drivers and general characteristics of the software evolution phenomenon.

The two perspectives are related in various ways: the study of the what/why is for instance essential to achieve an appropriate management of software engineering activities, and to guide innovation in processes, methods and tools, that is, the how. The output of the what/why studies is exemplified by empirical hypotheses, such as the staged model of software evolution.

This paper focuses on the commonalities and differences between the evolution and patterns in the lifecycles of traditional commercial systems and free/libre/open source software (FLOSS) systems. The existing staged model for software evolution is therefore revised for its applicability on FLOSS systems.