Closing the Gap Between Object-Oriented Modeling of Structure and Behavior

The UML as standardized language for visual object-oriented modeling allows to capture the requirements as well as the structure and behavior of complex software systems. With the increasing demands of todays systems, behavior aspects like concurrency, distribution and reactivity become more important. But the language concepts of the UML for describing behavioral aspects are weak compared to its concepts for describing structures. Besides a lack of visual expressiveness, a deeper integration with the structure specification is missing. In order to close this gap, an expressive language for modeling object-oriented behavior is proposed with the OCoN approach. It describes contracts, object scheduling as well as control and data flow of services in a Petri-net-like form. A seamless visual embedding of contract specifications into service and object scheduling specifications is provided by different net types.