Verbalizing Business Rules : Part 14

Business rules should be validated by business domain experts, and hence specified in a language easily understood by business people. This is the fourteenth in a series of articles on expressing business rules formally in a high-level, textual language. The first article [3] discussed criteria for a business rules language, and verbalization of simple uniqueness and mandatory constraints on binary associations. Article two [4] examined hyphen-binding, and verbalization of internal uniqueness constraints that span a whole association, or that apply to n-ary associations. Article three [5] covered verbalization of basic external uniqueness constraints. Article four [6] considered relational-style verbalization of external uniqueness constraints involving nesting or long join paths, as well as attribute-style verbalization of uniqueness constraints and simple mandatory constraints. Article five [7] discussed verbalization of mandatory constraints on roles of n-ary associations, and disjunctive mandatory constraints (also known as inclusiveor constraints) over sets of roles. Article six [8] considered verbalization of value constraints. Article seven [9] examined verbalization of subset constraints. Article eight [10] discussed verbalization of equality constraints. Article nine [11] covered verbalization of exclusion constraints. Article ten [12] dealt with verbalization of internal frequency constraints on single roles. Article eleven [13] considered verbalization of multi-role, and external, frequency constraints. Article twelve [14] discussed verbalization of ring constraints. Article thirteen [15] covered verbalization of basic subtype constraints. This article discusses why subtype definitions are needed, and how to verbalize them.