Calculated associations are not "real links" persited in database between WTpart and EPMdoc
They are calculated: from the WTpart, through the owner link to the 3D CADdoc, then to all Drawings that are linked by reference to this 3D model. But with a filter based on "As stored configspec"
I do not use this calculated links, and made some enhancement request to PTC to hide them (or overload them if both a calculated or a real content link exists). As depending of user scenario, (notably when revising / modifying Drawing alone), it changes the calculated link without any iteration or revision at the WTpart level . which is a non sense when using windchill with a part centric approach.