When defining equipment classes for use in master recipes in a batch controlled plant conforming to ISA-88 (IEC 61512) I am faced with a dilemma regarding setting up the plant model for use in master recipes.
Suppose I have an equipment class "Vessel".
Would I create derived classes for the various differences of the vessels or should I use a class property?
For example there may be heated vessels and unheated vessels, different volumes, different design pressures and/or different construction materials.
It seems that if vessels are all a bit dissimilar then creating a large bunch of derived classes feels like overkill and would make creating master recipes - with a high level of flexibility regarding unit selection - more challenging.
I'm trying to find the balance between using a single class or derived classes. What considerations are there, pros and cons from a maintainability point-of-view. Your thoughts?
Suppose I have an equipment class "Vessel".
Would I create derived classes for the various differences of the vessels or should I use a class property?
For example there may be heated vessels and unheated vessels, different volumes, different design pressures and/or different construction materials.
It seems that if vessels are all a bit dissimilar then creating a large bunch of derived classes feels like overkill and would make creating master recipes - with a high level of flexibility regarding unit selection - more challenging.
I'm trying to find the balance between using a single class or derived classes. What considerations are there, pros and cons from a maintainability point-of-view. Your thoughts?