BPMN21 — Conditions for completion of Process and Sub-Process

i) Chapter/Section 10.4.2. Page 245. It says:

“There MAY be multiple Start Events for a given Process level.

• Each Start Event is an independent Event. That is, a Process instance SHALL be generated when
  the Start Event is triggered.”

ii) Chapter/Section 13.1. Page 440. It says:

“To specify that the instantiation of a Process waits for multiple Start Events to happen, a Multiple Parallel Start
Event can be used.”

“Note that two Start Events are alternative, A Process instance triggered by one (1) of the Start Events does not wait
for an alternative Start Event to occur.”

“Note that there MAY be multiple instantiating Parallel Event-Based Gateways.
This allows the modeler to express that either all the Events after the first Gateway occur or all the
Events after the second Gateway and so forth.”

“Each Start Event that occurs creates a token on its outgoing Sequence Flows, which is followed as described by the
semantics of the other Process elements.”

iii) Chapter/Section 13.4.6. Page 458. It says:
“The Process instance is then completed, if and only if the following two conditions hold:”

• All start nodes of the Process have been visited. More precisely, all Start Events have been triggered,
  and for all starting Event-Based Gateways, one of the associated Events has been triggered.”

iv) Chapter/Section 13.4.6. Page 459. It says:
“The Sub-Process instance is then completed, if and only if the following two conditions hold:

• All start nodes of the Sub-Process have been visited. More precisely, all Start Events have been triggered,
  And for all starting Event-Based Gateways, one of the associated Events has been triggered.”

COMMENTS:

>From and (ii) can be deduced that each tart node (start event or start event-based gateway) is independent, i.e. the activation of one of them generates an new independent instance of the Process.

But in (iii) and (iv) it is said that all start nodes must be visited as a pre-condition to complete the execution of the Process instance. This contradicts what it is stated in and (ii).

SUGGESTIONS:

Modify (iii) and (iv) to make them consistent with what it is stated in and (ii).

Typo in (ii): “… are alternative, A Process instance…” should be replaced by “… are alternative. A Process instance…”