Improving UML Design Tools by Formal Games

The Unified Modeling Language (UML) [7] is a standardlanguage for modelling the design of object oriented softwaresystems. The currently available UML design toolsmainly provide support for drawing the UML diagrams, i.e.for recording a chosen design, but not for choosing a design.The design of a system is a non-trivial, iterative process anderrors which are introduced at this level are usually veryexpensive to fix. Hence we argue that UML design toolsshould provide more support for the design activity as such.Ideally a UML design tool should allow the modeller toexplore different design options, provide feedback about thedesign in its current state, and even make suggestions forimprovements where this is possible. The usage of such atool would be highly interactive and very much like a game,played repeatedly between modeller and tool. We claimthat this similarity makes formal games a natural and intuitivechoice for the definition of tool concepts. Since formalgames can be used for verification, a game-based tool canprovide feedback about flaws in the design that is formallyfounded.Games as used in verification normally require a completeformal model of the software system, and a formalspecification of the property that is to be verified. Instead ofthis we would like to let the designer play a game directlyon the basis of the UML model, even though a UML modelis often incomplete and informally defined. We also wantto allow the modeller explore variations of the design whilethe game is being played.The research hypothesis for this work is that formalgames are a suitable technique for more advanced UML designtools which point the modeller to .aws in the design,help to improve the design and provide support for makingdesign decisions.