Business Rule Modality

A business domain is typically constrained by business rules. In practice, these rules often include constraints of different modalities (e.g. alethic and deontic). Alethic rules impose necessities, which cannot, even in principle, be violated by the business. Deontic rules impose obligations, which may be violated, even though they ought not. Conceptual modeling approaches typically confine their specification of rules to alethic rules. This paper discusses one way to model deontic rules, especially those of a static nature. A formalization based on modal operators is provided, and some challenging semantic issues are examined from both logical and pragmatic perspectives. Because of its richer semantics, the main graphic notation used is that of Object-Role Modeling (ORM). However, the main ideas could be adapted for UML and ER as well. A basic implementation of the proposed approach has been prototyped in a tool that supports automated verbalization of both alethic and deontic rules.