A Bigraphical Model of WSBPEL

In this paper, we give a bigraphical model for web services composition. We investigate how to represent scope-based compensation handing mechanism by means of Bigraphical Reactive Systems (13RSs for short), which have been proposed to provide a uniform way to model spatially distributed systems that both compute and communicate. The service composition language we focus on is WSBPEL, which is the standard of web service composition and orchestration. This bigraphical model can be regarded as a unifying semantics of BPEL-like languages with the key concepts related to compensation handling. The rationality of the model is discussed by investigating the relationship between BPEL language and BRSs. Based on the bigraphical model, the algebraic laws for BPEL are proved as well.