Impact of software rejuvenation. Results of literature study

Software rejuvenation, also known as software restructuring or legacy removal, plays a critical role in preserving and enhancing the value of software assets within organizations. However, rejuvenation work can be difficult and tedious, and the benefit is not always clear. Therefore many individuals and organizations are reluctant to perform it. To facilitate rejuvenation tasks, TNO-ESI has been developing a suite of methods and tools collectively known as Renaissance. Now we want to measure the impact of these methods and tools on the organizations that adopt them.
This report reflects the initial part of a study into this impact measurement. This initial part consisted of studying literature, synthesizing a comprehensive theoretical framework, and investigating ways of measuring the various concepts in the theory. During the literature study we noticed that the various publications zoom in on specific aspects that are relevant, but a complete overview is missing. Therefore we constructed a theoretical framework that spans areas of software engineering, psychology, and economics. This is necessary because the impact of software rejuvenation is a sociotechnical phenomenon.
During the study, we identified two concepts deserving greater emphasis: the value of highly maintainable software, which enables efficient development of new features, and the job satisfaction of software developers, which influences their willingness to remain in their current roles.
For the various concepts in the theory, the report provides concrete ways of measuring them. It turns out that it is more complicated than we thought to measure exactly the right things. For some concepts, such as software maintainability, the measures favored in literature are too simple and do not cover essential aspects. For other concepts it is not easy to separate the effects of rejuvenation from those of other factors. The consequence of all this is that assessing the impact of software rejuvenation needs to take place in a way that is specifically tailored to the developing organization.
As the next step in our study we propose engaging in discussions with industrial partners of TNO-ESI. The appendix of the report provides a list of questions that may guide these discussions in order to obtain a better understanding of the situation in each organization and to prepare for tailored impact measurements.