BPMN2 — Clarification of Temporal Sematics of Sequence Flow

While tokens may help explain behavior, the specification should not rely on the concept of tokens to define the normative behavior of model elements.

Sequence flows represent temporal constraints requiring that an "incoming" constraint be satisfied before a flow element can be executed. The specification should refer to the sequence of execution or the flow of control rather than the flow of tokens.

While the specification explicitly says that tokens are a theoretical concept for explanation of behavior, the specification refers to the flow of tokens in many places. For example, the end event behavior is described as "The Process will be in a running state until all tokens are consumed."

Since tokens are not required for compliance, the normative definitions of behavior should not be specified in terms of token flows but in terms of satisfaction of temporal constraints.

Consistent use of temporal constraint semantics is importnant for specialization of processes (addition of intervening elements) and analysis of processes such as validation of compliance with a choreography.

Close; No Change. The FTF decided that the issue report does not identify a problem with the BPMN 2.0 specification
Disposition: Closed, No Change