Software evolution: Models and challenges

Developing software of large size is a difficult task. To maintain them and to make them evolve during numerous years is more difficult again. In the absence of a global vision, the software structure aim to be destroyed naturally with the progression of the modifications. Understanding the software is then more and more difficult. Several works attempted to capture software evolution from different perspectives. In this paper, we suggest a comparative classification of these works by presenting the most recent models of software evolution in every class.