A Component Framework where Port Compatibility Implies Weak Termination

The design and verification of an asynchronous communicating system can be very complex. In this paper we focus on weak termination: in each reachable state, the system has the option to eventually terminate. We present a component framework and construction method that guarantees weak termination. In the framework, communication between components is modeled by portnets, a special class of workflow nets. A basic component defines the orchestration of the portnets. For weak termination, the orchestration should accord to each of the portnets. A composite component is built from basic components that offer some service via a portnet. We provide sufficient conditions to guarantee weak termination for composite components. Furthermore, we present a refinement-based construction procedure to derive a weakly terminating composite from an architectural diagram of the system.