A new technique to analyze the control-flow, i.e., the workflow graph of a business process model, which is called symbolic execution, is provided. Acyclic workflow graphs that may contain inclusive OR-gateways are considered; a symbolic execution for them is defined, which runs in quadratic time. In particular, this symbolic execution essentially comprises labeling edges of nodes of the graph such that a label assigned to a first edge comprises a set of one or more edge identifiers, each identifying a second edge that is an outgoing edge of an XOR-split or an IOR-split node in the graph, whereby executing the second edge ensures that the first edge will be executed. Such a scheme may permit a decision for any pair of control-flow edges or tasks of the workflow graph whether they are sometimes, never, or always reached concurrently. This has different applications in finding control- and data-flow errors.