A Property may represent an attribute of a Classifier, a memberEnd of an Association, or in some cases both simultaneously. Source Unified Modeling Language 2.5.1
SysMLv1: MagicDraw/Cameo: Oh no, I lost my part or reference property? Where did it go? The Symbol Properties option for 'Show Association ends as Attributes' may help you find it!
SysMLv1: A part Property or reference Property is not necessarily a 'memberEnd' or 'ownedEnd' of an Association ('association' or 'owningAssociation'). But an Association always as at least 2 'memberEnd' Properties. (With some MagicDraw/Cameo tool tips.)
If the StructuralFeature is an Association end, the semantics are the same as for a CreateLinkAction ..., where the participants in the link are the object being acted on and the new value. Source Unified Modeling Language 2.5.1