I am using the Product Line Engineering plugin with a relatively simple model in Cameo Enterprise Architecture 2022xR2-HF3 that is malfunctioning in some configurations. I have traced the problem to an Existence Validation Point (EX VP) and an Element Property Validation Point (EP VP) that act on a Part Property and its Type. This bad behavior happens when the EX VP is evaluated before the EP VP; in the opposite order, the Validation Transformation works correctly. (I have verified this by putting javascript in the expression property of both of these VPs to emit a diagnostic message to the Notification Window.)

I recognize constraints are declarative by UML definition, but in practice they are evaluated in some order, and PLE plugin does not always evaluate these in the same order from transformation to transformation.

Is there a way to ensure that this particular EX VP (which removes a Part Property) is evaluated after that particular EP VP (which changes the Type of the Part Property)? (This behavior is valid and necessary in various configurations.) Can I define a class of VPs the evaluate in order?

I noticed they evaluate in the same Java thread, so I can't play games with delays (calling java.lang.Thread.currentThread().getId()).

I have tried to add "steps" (chained Feature Groups with untyped Feature Properties) in the Feature Model to try to encourage the EP VP to evaluate before the EX VP.

I have also tried to create these elements in the order I want them to evaluate (by their element IDs); I have sorted them in their containing package and neither of these work.

I have noticed that the EP VP will complain that it cannot change the property because the Part Property is not present in the model (the EX VP removed it). Is there a way to "trap" these errors, and/or skip the EX VP evaluation if its constrained element does not exist?

Is there an object I can query to get the evaluation status of a particular constraint, and maybe trigger the evaluation of a desired constraint?

Is there a property in in either of these variation point elements that can help. How about Feature Path, or Pre Context / Post Context? None of these have any nor any useful documentation, BTW.

Ideas? Anyone? What say you @DB  ?