Mechanisms for incorporating a human into an automated multiple-entity scenario simulation are disclosed. A Petri-net message processor function (PMPF) receives a first Petri-net message from a source activity node function (ANF). The Petri-net message includes a simulation activity identifier that identifies a first simulation activity. The PMPF routes the first Petri-net message to a first ANF based on the simulation activity identifier. The first ANF receives the first Petri-net message and provides a message to a user based on the first Petri-net message. A response is received from the user. A second Petri-net message is generated based on the response and is communicated to a destination ANF to trigger a second simulation activity by the destination ANF.