Contingent level classes
Ulrich Frank, Daniel Töpel · 2020
It has been known for some time that the level of a class may vary with the context it is used in. There are a few approaches that enable modelers to deal with corresponding requirements. However, they usually provide workarounds to avoid the problem of one class being on different levels at the same time. In this paper, the need for those classes, which are called contingent level classes, is motivated from a conceptual perspective. A conceptualization of contingent level classes is presented that addresses principal integrity issues and accounts for resulting constraints on class properties and relationships. Based on that conceptualization, the paper provides an analysis of specific challenges related to change operations on models that include contingent level classes. Subsequently, a set of patterns for coping with certain kinds of change operations is presented.