Verification of time-aware business processes using constrained Horn clauses

We present a method for verifying properties of time-aware business processes, that is, business processes where time constraints on the activities are explicitly taken into account. Business processes are specified using an extension of the Business Process Modeling Notation (BPMN) and durations are defined by constraints over integer numbers. The definition of the operational semantics is given by a set OpSem of constrained Horn clauses (CHCs). Our verification method consists of two steps. (Step 1) The specialization of OpSem with respect to a given business process and a given temporal property to be verified. This specialization produces a set of CHCs whose satisfiability is equivalent to the validity of the given property. (Step 2) The use of any state-of-the-art solver for CHCs to check the satisfiability of such sets of clauses. We have implemented our verification method using the VeriMAP transformation system and the Z3 solver for CHCs.