OBSERV-a prototyping language and environment combining object oriented approach, state machines and logic programming

The OBSERV methodology for software development is based on rapid construction of an executable specification (or prototype) of a system, which may be examined and modified repeatedly to achieve the desired functionality. The objectives of OBSERV also include facilitating a smooth transition to a target system and providing the means for reusing specification, design, and code of (sub)systems. Of particular interest is the handling of embedded systems, which are likely to have concurrency and real-time requirements. The OBSERV prototyping language combines several paradigms to express the behavior of a system. The object-oriented approach provides the basic mechanisms for building a system from a collection of objects, with well-defined interfaces between them. Finite-state machines are used to model the behavior of individual objects. At a lower level, activities that occur within objects are described with the logic-programming paradigm, thus allowing a nonprocedural description when possible. An attempt has been made to provide flexible tools for executing (simulating) the prototype being built, as well as for browsing and static checking