SYSML2 — Assignment action usages do not specify when their expressions are evaluated

Clause 8.3.16.5 (AssignmentActionUsage), Description, says:

An AssignmentActionUsage is an ActionUsage that is defined, directly or indirectly, by the ActionDefinition AssignmentAction from the Systems Model Library. It specifies that the value of the referent Feature, relative to the target given by the result of the targetArgument Expression, should be set to the result of the valueExpression.

but does not require the model to specify when the expression is evaluated (or its owner, AFAICT).