On the concurrency of inter-organizational business processes

Within organizations, workflow systems can automate business processes by centrally coordinating activity sequences. But outside their borders, organizations are autonomous entities that cannot be subject to centralized process control. Their internal processes are autonomously defined and controlled, and what they need is to synchronize those concurrent processes. Just like Petri nets are a valuable tool to model activity sequencing in local business processes, pi-calculus becomes a useful tool to model concurrency in inter-organizational processes. After a review of the main developments in cross-organizational workflow management, this paper illustrates the use of pi-calculus to model the interactions between business processes running concurrently in different organizations. These interactions range from invoking external services to more complex patterns such as contract negotiation and partner search and selection. The paper concludes with a case study that illustrates the application of the proposed approach in a more realistic business scenario.