InterPlay: Horizontal Scale-Up and Transition to Design in Scenario-Based Programming

We describe InterPlay, a simulation engine coordinator that supports cooperation and interaction of multiple simulation and execution tools, thus helping to scale up the design and development cycle of reactive systems. InterPlay involves a number of related ideas. In the first, we concentrate on the interobject design approach involving live sequence charts (LSCs) and its support tool, the play-engine, enabling multiple play-engines to run in cooperation. This makes possible the distributed design of large-scale systems by different teams, as well as the refinement of parts of a system using different play-engines. The second idea concerns combining the interobject approach with the more conventional intraobject approach, involving, for example, statecharts and Rhapsody. InterPlay makes it possible to run the play-engine in cooperation with Rhapsody, and is very useful when some system objects have clear and distinct internal behavior, or in an iterative development process where the design is implementation-oriented and the ultimate goal is to end up with an intraobject implementation. Finally, we have expanded the play-engine's ability to delegate some of the system's functionality to complex GUIs. This enables beneficial interaction with "smart" GUIs that have built-in behavior of their own, and which are more naturally implemented in code