Usability Assessment of a UML-based Formal Modelling Method

Conceptual models communicate the important aspects of a problem domain to stakeholders. The models therefore should be accessible to users who need to interpret them. On the other hand, the quality of the produced models is highly dependent on the usability of the modelling method used. This paper presents a series of usability assessments conducted on a method that integrates the use of a semi-formal notation, namely the Unified Modelling Language (UML) and a formal notation, namely B. The assessments included a controlled experiment that evaluated the comprehensibility of the produced model and a survey that assessed the modelling process. The results suggest that the method is able to produce a comprehensible model. The method is accessible to users when the principles and roles of each notation are obvious and well understood, and when there is strong support from the environment.