Patent ID: 8572551

Claim:
A method for production in a data processing system of a difference log defining differences between a plurality of process models defined in memory of the system, the method comprising: for each process model of the plurality of process models, providing, in a memory, model structure data defining a hierarchy of Single-Entry-Single-Exit (SESE) regions representing the structure of that process model; providing, in the memory, model comparison data defining correspondences between elements of the process models; comparing regions of the SESE region hierarchies defined by said model structure data to detect correspondences between regions and to generate region comparison data defining the correspondences and providing, in the memory, region comparison data defining correspondences between regions of SESE region hierarchies for the process models; analyzing the model comparison data and the region comparison data to identify differences between the SESE region hierarchies; and producing a difference log defining said differences in the memory, the difference log indicating, for each difference, a region of at least one of said SESE region hierarchies in which that difference occurs.