An object-oriented modeling framework for petri nets and related models

In this paper, we introduce an object-oriented modeling framework called UMF for modeling with graph-based formalisms, such as Petri nets and related models. UMF is based on a four layered model for defining a concrete model, including meta-formalism, formalism, model class and models. We have defined these concepts formally and have provided a sample model for showing how to use them in UMF. We have used the object constraint language (OCL) for precise definition of formalism in UMF. There is also an innovative model composition approach in UMF, which is more flexible than other existing approaches for composing models of variant types.