On Integrating Structure and Behavior Modeling with OCL

Abstract

AbstractPrecise modeling with UML and OCL traditionally focuses on structural model features like class invariants. OCL also allows the developer to handle behavioral aspects in form of operation pre- and postconditions. However, behavioral UML models like statecharts have rarely been integrated into UML and OCL modeling tools. This paper discusses an approach that combines precise structure and behavior modeling: Class diagrams together with class invariants restrict the model structure and protocol state machines constrain the model behavior. Protocol state machines can take advantage of OCL in form of OCL state invariants and OCL guards and postconditions for state transitions. Protocol state machines can cover complete object lifecycles in contrast to operation pre- and postconditions which only affect single operation calls. The paper reports on the chosen UML language features and their implementation in a UML and OCL validation and verification tool.KeywordsStructure modelingBehavior modelingUMLOCLProtocol state machineState invariantGuardTransition postcondition