Towards an Approach to Identify Obsolete Features based on Importance and Technical Debt

Many of today's software systems are maintained over years or even decades. To ensure that software remains useful, new features have to be added or old features have to be adapted to respond to new or changed requirements. As time goes on, some of the features become obsolete, i.e., are not needed anymore. Typically, these features are not removed because of various reasons, e.g., because removing them might be considered too costly, the costs of keeping unused features is considered low, or because of the "sunk cost fallacy", i.e., that a feature is considered worth to keep because of the previously invested resources (time, money or effort) to build it. The consequences of keeping unused source code can impact maintainability, technical debt, performance, and extensibility of the system. This can lead to lower development productivity and to a reduced innovation ability, consequently reducing competitiveness on the market. This paper aims to present an approach to identify features based on their value and on costs for keeping or removing them.