An “80-20” Approach to the Study of Coupling
Steve Counsell, Stephen Swift, Amjed Tahir · 2023
In this paper, we use both afferent (i.e., incoming) and efferent (i.e., outgoing) class coupling to analyse trends in seven open-source and four industrial systems. We determine whether an 80-20 rule (or Pareto’s Law) applies to either type of coupling and whether 20% of classes contain 80% of coupling (whether incoming and outgoing). We also explore the relationship between bugs and both types of coupling. Results showed that an 80-20 rule applied overwhelmingly in the industrial systems (but not in the open-source). For the two types of coupling, the open-source systems also had a stronger, positive relationship with bugs; opposite effects were found in the industrial systems. These results highlight the need for adoption of different and impactful approaches to understanding systems which reflect on developer practice.