Formal Ver ification of Workflow Schemas

Practical experience indicates that the definition of real-world workflow applications is a complex and error-prone process. Existing workflow management systems provide the means, in the best case, for very primitive syntactic verification, which is not enough to guarantee the overall correctness and robustness of workflow applications. The report introduces a method for formal verification of system behaviour which, in C3DS, is defined as workflow schemas. Workflows are modelled by means of an automata-based method, which facilitates exhaustive compositional reachability analysis. The workflow behaviour is checked against safety properties, which can be either generic (applicable to all workflow schemas) or domain specific (applicable to a given schema). The analysis is performed in an automated way using the LTSA toolkit, which is accessible by designers who are not experts in formal methods.