OCLR: A more expressive, pattern-based temporal extension of OCL

Modern enterprise information systems often require to specify their functional and non-functional (e.g., Quality of Service) requirements using expressions that contain temporal constraints. Specification approaches based on temporal logics demand a certain knowledge of mathematical logic, which is difficult to find among practitioners; moreover, tool support for temporal logics is limited. On the other hand, a standard language such as the Object Constraint Language (OCL), which benefits from the availability of several industrial-strength tools, does not support temporal expressions. In this paper we propose OCLR, an extension of OCL with support for temporal constraints based on well-known property specification patterns. With respect to previous extensions, we add support for referring to a specific occurrence of an event as well as for indicating a time distance between events and/or from scope boundaries. The proposed extension defines a new syntax, very close to natural language, paving the way for a rapid adoption by practitioners. We show the application of the language in a case study in the domain of eGovernment, developed in collaboration with a public service partner.