Lifecycle based study framework of software evolution

Software evolution is characterized by its changing in accord with environment and requirement. It is one of the most difficult and important problems of software. From the runtime perspective, it includes two types: static evolution and dynamic evolution. Static evolution is mainly implemented by human static intervention and analysis. Dynamic evolution is based on the runtime evolution of software, mainly characterized as software self-adapting to environment. This paper presents a change-tracing model that regards the change as the starting point and focuses on software evolution in OO paradigm. It illustrates the change transmission and implementation process during the whole software lifecycle. Concerning the similarity between the change transmission process and the software lifecycle, a research framework of software evolution is proposed. This framework integrates all elements that are involved in the change transmission process, such as scenario, object, component and SA (Software Architecture). Based on this framework, the research of software evolution will be more effective and ties in dynamic evolution. At the end of paper, it gives some detailed discussion of key problems of software evolution in the framework and the corresponding solvability ideas.