CoConstraintDimensionEffect

Co-Constraint Dimension: Effect

In message Analysis of use cases for co-constraints Fabio Vitali proposed a set of dimensions for the evaluation of co-constraints use cases. This is an explanation of dimension effect.

Effect: the kind of effect the dependency has on the destination

• FLAG: Just raise a validation error
• UPGRADE: Optional structure becomes required, nillable structure becomes non-nil
• DOWNGRADE: Optional structure must not appear, nillable structure becomes nil
• MUTUAL PRESENCE: both structures must appear together or none
• MUTUAL EXCLUSION: either structure must appear, but not both. None appearing is acceptable
• ALTERNATIVE EXCLUSION: either structure must appear, but not both. One must appear.
• RESTRICTION: a normally acceptable structure is not acceptable
• RELAXATION: a normally unacceptable structure is acceptable
• CHOICE OF TYPE: one of multiple content models is chosen
• NOT CLEAR: use case does not explain the effect