A Visualization of OCL using Collaborations

We propose a visualization of OCL within the context of the UML meta model, so that OCL expressions are represented by extending collaboration diagrams. We exploit the OCL meta model introduced in [9] and further elaborated on in [1] and base the description of properties of objects on collaborations, while classifier and association roles are used to describe navigation paths. Operations computing properties are described by interactions consisting of messages between classifier roles. The introduction of new graphical core elements is kept to a minimum. New notation mainly concerns the predefined operations in OCL and provides more convenient visual forms for the notation by interactions here. The proposed visualization is described in detail and is illustrated with examples taken from an industrial project under development.