Pattern 3 (Compacting)

FLASH animation of Compacting pattern


This pattern refers to methods to remove re- dundant or superfluous elements in a process model, e.g. redundant transitive arcs, gateways or duplicated tasks. Thus, it may revert the effects of Duplication.


Fig. 3b can also be obtained by compacting the two occurrences of task Reject loan and the two XOR-split gateways from the model in Fig. 4.


To reduce model size and thus improve the overall model representation, especially in large process models or models that have undergone a number of updates.


Reduces model size.


Reducing model size positively affects model un- derstanding [80].


Methods for eliminating superfluous elements have been defined for Petri nets. The work by Berthelot defines so-called implicit places [17], [16]. An implicit place does not contribute to the overall behavior captured in a process model, since it always has a token when other places have tokens too. Thus, it can be deleted without impacting the model behavior. A related reduction rule is defined by Desel and Esparza [32] with the notion of transitively dependent arc. While this concept is defined for verification purposes, it can also be used to eliminate superfluous arcs from a process model without an effect on the behavior. The concept of transitive reduction is also exploited in an approach to synthesize process models from behavioral profiles such that transitive order dependencies are deleted [108]. Furthermore, [33] proposes an approach to merge subsequent connectors of the same type. The same idea is utilized in [77].