Empirical evaluation of the understandability of architectural component diagrams

The architecture of a software system plays a crucial role during evolution and maintenance, as it provides the means to cope with the inherent system complexity by abstracting from implementation and design details. Architectural component models represent high level designs and are frequently used as a central view of architectural descriptions of software systems. Hence, understandability of those models is crucial as they play a key role in supporting the architectural understanding of a software system. In this paper we present the results from a study we carried out to examine to which extent the software architecture could be conveyed through architectural component diagrams. The statistical evaluation of the results shows that metrics such as the number of components, number of connectors, number of elements, and number of symbols used in the diagrams can significantly decrease architectural understandability when they are above and below a certain, roughly predicted threshold. Also, our results indicate that architectural understandability is linearly correlated with the perceived precision and general understandability of the diagrams.