OCL Constraints Generation from Natural Language Specification

Object Constraint Language (OCL) plays a key role in Unified Modeling Language (UML). In the UML standards, OCL is used for expressing constraints such as well-definedness criteria. In addition OCL can be used for specifying constraints on the models and pre/post conditions on operations, improving the precision of the specification. As a result, OCL has received considerable attention from the research community. However, despite its key role, there is a common consensus that OCL is the least adopted among all languages in the UML. It is often argued that, software practitioners shy away from OCL due to its unfamiliar syntax. To ensure better adoption of OCL, the usability issues related to producing OCL statement must be addressed. To address this problem, this paper aims to preset a method involving using Natural Language expressions and Model Transformation technology. The aim of the method is to produce a framework so that the user of UML tool can write constraints and pre/post conditions in English and the framework converts such natural language expressions to the equivalent OCL statements. As a result, the approach aims at simplifying the process of generation of OCL statements, allowing the user to benefit form the advantages provided by UML tools that support OCL. The suggested approach relies on Semantic Business Vocabulary and Rules (SBVR) to support formulation of natural language expressions and their transformations to OCL. The paper also presents outline of a prototype tool that implements the method.