Model and Object Verification by Using Dresden OCL

1 The Object Constraint Language (OCL) is a formal language standardized by the OMG (Object Management Group) that allows the specification of constraints on MOF(Meta Object Facility) or EMF (Eclipse Modeling Framework) Ecore-based models. After about ten years of research and OCL prototyping in the area of using formal methods in practical software engineering, OCL is appreciated by the industry and tool vendors. An often used OCL library is the Dresden OCL Toolkit. OCL can be applied both on the meta-model (M2) and on the model layer (M1). In this paper we present use cases for OCL in the context of the Dresden OCL Toolkit. We show how the user is able to specify precise semantics both on the meta-model and the model layer by OCL, and how these OCL constraints can be verified on models respectively on objects.