An improvement method for the workflow management systems based on the reallocation of flows using the genetic programming and its applications

This paper deals with an improvement method for the Workflow Management Systems (WMSs) based on the reallocation of flows using the Genetic Programming (GP) and its applications. Current WMSs are usually used in a static manner and WMSs are designed based on conventional experiences. It is also necessary to modify the system by observing the failed tasks. We propose a method for the improvement and reconfiguration of WMSs based on the GP. It is expected that the scheme of approximation of chaotic dynamics by using the GP is extended to the WMS design. In our method, each activity on WMSs is assumed to be a function having several inputs, and the combination of these functions and sequences of the functions are improved by using the GP. Links combining nodes are assumed to be flows in networks. The syntactical validity of the individuals is checked by using a kind of counter for the parse tree obtained in the prefix representation. If the validity is not satisfied, the individual is removed from the pool of individuals. In the improvement, the evaluation function is composed of the completion of underlying objectives as well as conventional measures such as costs and waiting time. We apply the crossover operations to the individuals possessing relatively higher fitness in the reproduction phase. The mutation operation is utilized especially to determine the configuration of split operations by reintroducing some diversity. By using the result of simulation, sequences of database access obtained by the flows in WMSs are examined whether they included at least the control sequence imposed on the underlying WMS realization. The method is applied to the improved design of WMSs and the extension to the hierarchical system design.