Since 3.1
Manual task execution allows user to invoke task processing. Task is entity which describes how to react to some source event. So normally task is processed only as a response to some source event. Since 3.1 user can manually invoke task processing.
In addition user can specify some parameters to simulate source event which would normally trigger task processing. Following figure displays how could be simulated "file event". Parameters for various event sources are listed in section "Graph parameters"