To UML or not to UML?: Empirical Study on the Approachability of Software Architecture Diagrams

Software architecture design is key to building systems that meet quality demands. Choosing the appropriate way to model the architecture ensures it is rightly understood by everyone involved. UML diagrams are commonly used in software engineering but free-form diagrams are almost as common. In this paper, we study the factors influencing the approachability of diagrams, and particularly whether there is a difference in the approachability between UML and non-UML diagrams and colored and black & white diagrams. Our results show that colors do not necessarily increase the approachability of diagrams and free-form diagrams can suffer from ambiguousness. We conclude that simplicity and correctness are key factors when modeling architectures.