Towards Agent-Based Modeling and Verification of Collaborative Business Processes: an Approach Centered on Interactions and Behaviors

This paper presents the process-oriented aspects of a formal and visual agent-based business process modeling language. The language is of use for (networks of) organizations that elect or envisage multi-agent systems for the support of collaborative business processes. The paper argues that the design of a collaborative business process should start with a proper understanding of the work practice of the agents in the business domain under consideration. The language introduces a novel diagram to represent the wide range of (cross-enterprise) business interactions as a hierarchy of rolebased interactions (including their ordering relations) in a tree structure. The behaviors owned by the agents playing the roles in the tree are specified in separate process diagrams. A collaborative business process studied in the context of a case study at a Dutch gas transport company is used to exemplify the modeling approach. Explicit (agent-based) process models can and should be verified using formal methods. In the business process community, design-time verification of a process design is considered vital in order to ensure the correctness and termination of a collaborative business process. The proposed modeling approach is enhanced with a design-time verification method. The direction taken in this research is to combine the interaction tree and the associated agent behaviors into a verifiable hierarchical colored Petri net in order to take advantage of its welldefined (execution) semantics and proven (computerized) verification techniques. The verification method presented in this paper consists of three steps: (1) the translation of the agent-based process design to a hierarchical colored Petri net, (2) the identification of process design errors, and (3) the correction and rollback of process design errors to the agent-based model. The translation technique has been implemented in a software tool that outputs the hierarchical colored Petri net in a format that can be loaded in the widely used CPN Tools software package. Verification results are discussed for the case study model.