BPMN 2.1 RTF Avatar
  1. OMG Issue

BPMN21 — Multiple uncontrolled incoming Sequence Flows

  • Key: BPMN21-268
  • Legacy Issue Number: 15839
  • Status: open  
  • Source: scch.at ( Christine Natschlär)
  • Summary:

    According to Section 13.2.1:
    The presence of multiple incoming Sequence Flows behaves as an exclusive gateway.

    However, I think this is only the case for alternative paths (only one token). Otherwise, several instances are created. See the specification from other sections:

    An Activity MAY be a target for Sequence Flows; it can have multiple incoming Sequence Flows. Incoming Sequence Flows MAY be from an alternative path and/or parallel paths.

    If the Activity has multiple incoming Sequence Flows, then this is considered uncontrolled flow. This means that when a token arrives from one of the Paths, the Activity will be instantiated. It will not wait for the arrival of tokens from the other paths. If another token arrives from the same path or another path, then a separate instance of the Activity will be created.

    If all the incoming flow is alternative, then a Gateway is not needed.

    I think that only multiple alternative incoming flows correspond to an exclusive gateway. I, therefore, suggest the following adaptation:

    The presence of multiple "alternative" incoming Sequence Flows behaves as an exclusive gateway.

    or

    The presence of multiple incoming Sequence Flows may instantiate an Activity several times.

  • Reported: BPMN 2.0 — Mon, 22 Nov 2010 05:00 GMT
  • Updated: Fri, 6 Mar 2015 20:57 GMT