Graph oriented models are at the core of most business process management systems. In recent years, “algebraic” business process
modeling languages based on different process calculi have been proposed. The semantics of these algebraic process languages
are quite different, and seemingly incompatible, with those of graph oriented approaches. In this paper we study how the BPEL4WS
exception handling mechanism is used to integrate the algebraic and graph process models. Unlike other approaches to exception
handling in business processes, the BPEL4WS model does not require that the process topology be constrained by the exception
handling hierarchy, thus allowing both highly structured and graph based processes to benefit from it. Based on this exception
handling model, we explain “dead path elimination” (the runtime mechanism by which process termination is ensured) as a form
of exception processing. The integration of dead path elimination with the exception handling mechanism provides the semantic
base for the integration of the graph and algebraic processes models in BPEL4WS.
Subject Classifications Business process modeling - reference models - process patterns - workflow management systems