From Informal to Formal Specifications in UML

In this paper, we consider a way of bridging informal and formal specification. Most projects have a need for an informal description of the requirements of the system which all people involved can understand. At the same time, there is a need to make some of the requirements more formal. We present a way to relate informal requirements, in form of use cases, to more formal specifications, written in the Object Constraint Language (OCL). Our approach gives the customers of software systems a way of guiding the development of formal specifications. Conversely, the formal specification can improve the informal understanding of the system by exposing gaps and ambiguities in the informal specification.