Tool Support for Restricted Use Case Specification: Findings from a Controlled Experiment

Evidence has shown that the use of restricted natural languages can reduce ambiguities in textual use case specifications (UCSs). Restricted natural languages often come with specific editors that support particular use case templates and provide enforcement of the language’s restrictions. However, whether restriction enforcement facilitates the definition of UCSs as compared to an editor without such support is a fundamental question to answer. To this end, we report results of a controlled experiment in which we compared two approaches for defining restricted UCSs: (i) a specific Restricted Use Case Modeling (RUCM) tool that supports restriction enforcement; and (ii) a general Office Word UCS template without such enforcement. We compared both approaches from multiple perspectives including restriction misuse, understandability, and restrictiveness. Results show that the restriction misuse rates are generally low, which indicates the usefulness of the RUCM, independent of the use of the editors. The results also indicate that the RUCM tool eases the application of more complex restrictions. We also found that the participants profited from extensive training prior to the experiment. The experiment participants further showed their strong willingness to recommend the RUCM tool to others and to use it in the future, which was not the case for the Office Word template. Index Terms—Use case modeling, restricted natural language, controlled experiment.