Yet Another Real-Time Specification for the Steam Boiler: Local Clocks to Statically Measure Systems Performance

Correct component models for distributed, reactive systems are difficult to construct. Typically, the services provided by such systems emerge from the interaction and collaboration of multiple components; each component, in general, contributes to multiple services. Consequently, services and their defining interaction patterns are key elements in the development process for distributed system: they contain the cross-cutting aspects of collaboration, which are only poorly captured on the component level. Typical modeling and development methods and associated notations, such as the UML, however, focus on the specification of complete information about components, instead of on the partial view provided by services. In this contribution, we give a precise definition of the term service, based on patterns of interaction. Using the CTAS case study, we demonstrate systematic development steps leading from service specifications to component implementations; we also show how to automatically synthesize prototypic state machines from interaction patterns defining services.