Fast and formalized: Heuristics-based on-the-fly web service composition and verification

It is by no means a trivial task to ensure if a composition of web services is doing a right thing (i.e. fulfilling the service requirement from users, or hard constraints) and at the same time doing the thing right (i.e. achieving acceptable degree of service quality, or soft constraint). Difficulties lie on (i) unifying the verification of hard constraints and soft constraints of a service into a single automated process; and (ii) suffering the resource-consuming when performing either the composition or the verification task on real data. In this paper, we propose an approach to simultaneously compose and verify web services on both hard and soft constraints in an on-the-fly manner. Relying on model checking, we also propose some heuristics based on web service characteristics to improve the state searching performance of the model checker. Our approach has been implemented as a framework, known as OnTheFlyWCV, which has been evaluated on the real-world case studies and datasets. The experimental results demonstrated the effectiveness of our method, especially as compared to other existing works in the same field.