Reasoning on Workflow Evolutions

This paper presents a new formalism for modelling workflows schemes which combines a control flow graph representation with simple (i.e., stratified), yet powerful DATALOG rules to express complex properties and constraints on executions. Both the graph representation and the DATALOG rules are mapped into a unique program in , that is a recent extension of DATALOG for handling events. This mapping enables the designer to simulate the actual behavior of the modeled scheme by fixing an initial state and an execution scenario (i.e., a sequence of executions for the same workflow) and querying the state after such executions. As the scenario includes a certain amount of non-determinism, the designer may also verify under which conditions a given (desirable or undesirable) goal can be eventually achieved.