Characterizing Software Maintenance Categories Using the Linux Kernel Ayelet Israeli

Software maintenance involves different categories of activities: corrective, adaptive, perfective, and preventive. However, research regarding these distinct activities is h ampered by lack of empirical data that is labeled to identify the type of maintenance being performed. A promising dataset is provided by the more than 800 releases of the Linux kernel that have bee n made since 1994. The Linux release scheme differentiates be tw en development versions (which may be expected to undergo perf ctive maintenance) and production versions (probably dominated by corrective maintenance). The structure of the codebase a lso distinguishes code involved in handling different architectures and devices (where additions reflect adaptive maintenance) from the core of the system’s kernel. Assuming that these dissect ions of the codebase indeed reflect different types of activity, we d emonstrate that corrective maintenance does not necessarily le ad to code deterioration, that adaptive maintenance may improvesome quality metrics, and that growth is largely the result of continued development as part of perfective maintenance.