Constructing process models represented by simple Petri nets

The paper deals with the problem of “workflow mining.” Workflow mining is numerous techniques for discovering processes' models represented by their workflow log. The paper considers process models in terms of simple Petri nets. It is shown that constructing a correct model when a process contains equal tasks is not always an attainable goal. Moreover, it was revealed that in the case when a model has transitions with no correspondence to any process task, the relation between the causal relations detected in the log and the presence of places connecting transitions in the Petri net is violated.