Abstract
To prevent issues arising from legacy software platforms, adapting to changing customer needs by software evolution is a growing concern of software organizations. How-ever, current practices are pragmatic and subjective, which restricts benchmarking and reduces efficiency. In order to improve evolutionary practices, this paper proposes the Software Functionality Evolution Method (SFEM). The SFEM provides a software vendor with input for product roadmapping, by mapping functionality between software platforms. Mappings are based on characteristics and constraints of functionality, personas and software platforms. An incremental method engineering approach is put to practice, in which the template method is instantiated and improved over multiple cases. Cases show that the method contributes to efficient reasoning and strategic decision making in software evolution for software product managers.