Software evolution—Background, theory, practice

This paper opens with a brief summary of some 30 years of study of the software evolution phenomenon. The results of those studies include the SPE program classification, a principle of software uncertainty and laws of E-type software evolution. The laws were termed so because they encapsulate phenomena largely independent of the people, the organisations and the domains involved in the evolution of the E-type systems studied. Recent studies have refined earlier conclusions, yielded practical guidelines for software evolution management and provide a basis for the formation of a theory of software evolution. Given the volume of published material and the extent of recent discussions on the topic (see, e.g., [Proc. ICSM, Montreal, 2002, p. 66]), this paper is restricted to an overview that exposes the significance of the evolution phenomenon and its study to the wider community, providing a basis for the future and, in particular, development of a theory of software evolution.