Is Self-Admitted Technical Debt a Good Indicator of Architectural Divergences?

Abstract

Large software systems tend to be highly complex and often contain unaddressed issues that evolve from bad design practices or architectural implementations that drift from definition. These design flaws can originate from quick fixes, hacks or shortcuts to a solution, hence they can be seen as Technical Debt. Recently, new work has focused on studying source code comments that indicate Technical Debt, i.e., Self-Admitted Technical Debt (SATD). However, it is not known if addressing information left by developers in the form source code comments can give insight about the design flaws in a system and have the potential to provide fixes for bad architectural implementations. This paper investigates the possibility of using SATD comments to resolve architectural divergences. We leverage a data set of previously classified SATD comments to trace them to the architectural divergences of a large open source system, namely ArgoUML. We extract its conceptual and concrete architectures based on available design documentation and source code, and contrast both to expose divergences, trace them to SATD comments, and investigate their resolution. We found 7 high-level divergences in ArgoUML and 22 others among its subsystems, observing that merely 4 out of 29 (14%) divergences can be directly traced to SATD. Although using SATD as an indicator of architectural divergences is viable, the effort of doing so is time-intensive, and in general, will not lend to a significant reduction of architectural flaws in a software system.