The Gap between the Admitted and the Measured Technical Debt: An Empirical Study

Technical debt is a well understood and used concept in IT development. The metaphor, rooted in the financial world, captures the amount of work that development teams owe to a product. Every time developers take a shortcut within development, the technical debt accumulates. Technical debt identification can be accomplished via manual reporting on the technical debt items, which is called self-admitted technical debt. Several specialised methods and tools have also emerged that promise to measure the technical debt. Based on experience in the community, the impression emerged that the measured technical debt is of a significantly different amount than the self-admitted debt. In this context, we decided to perform empirical research on the possible gap between the two. We investigated 14 production-grade software products while determining the amount of accumulated technical debt via (a) a self-admitting procedure and (b) measuring the debt. The outcomes show clearly the significant difference in the technical debt reported by the two methods. We urge development and quality-assurance teams not to rely on technical debt measurement alone. The tools demonstrated their strength in identifying low-level code technical debt items that violate a set of predefined rules. However, developers should have additional insight into violations, based on the interconnected source code and its relation to the domain and higher-level design decisions.