An DurationConstraint asserts that a Model Element (which becomes a ‘constrainedElement’) exists during a duration in time, possibly relative to some given set of observations.
▪If the Duration has an expr, then this is evaluated to produce the result of the DurationExpression. The expr must evaluate to a single value.
▪The expr may reference the observations associated with the Duration.
▪If the Duration has an expr but no observations, then the expr evaluates to a duration constant.
▪If the Duration does not have an expr, then it must have a single DurationObservation and the result of that observation is the value of the Duration.
How to specify a Duration Constraint
1 Create the DurationConstraint as a definition through the Explorer or by drawing an DurationConstraint on a diagram.
2 Create a Constraint to ConstrainedElement relationship between the DurationConstraint (in the example below, the constraint “Form Timeout”) and a Classifier (in the example below, the class “Web Form”) either by drawing the relationship on a diagram or by specifying the ConstrainedElement (in this case the class “Web Form”) in Constraint tab of the DurationConstraint definition
3 In the DurationConstraint definition, create its Specification – which is a DurationInterval definition.
4 Specify a max or min value of the Duration in the appropriate tabs of the DurationConstraint definition. In either case you create a Duration definition. In the Duration definition, specify:
