DTV — Clause 5.2 depicts the UML model as informative

In Clause 5.2, in explaining the conventions used for the UML models, the first two paragraphs contain the follwing text:

"The intent of the model is two-fold: (a) to illustrate this vocabulary with UML diagrams; (b) to satisfy the RFP requirement for a matching UML model.

The UML model is derived manually from the SBVR-based text in this document. In case of any discrepancies between the SBVR-based text in this document and the UML model, the text prevails because it is the original model."

This text suggests that the purpose of the UML model is illustrative, rather than normative, and that it is derived from, and inferior in status to, the SBVR model. Bullet (b) belies the rest – the RFP asked for a normative UML model. This specification presents one, and that is what should be said here.

The Date/Time Vocabulary is (mostly) presented as a formal SBVR "business vocabulary" using the text conventions of SBVR. Clause 5.1 should say that, and does not. The interpretation of the vocabulary presentation is more important than the use of SBVR Structured English as the pseudo-formal form for definitions. It is the interpretation of the vocabulary structure that leads to the normative SBVR XML files attached to the specification.

The UML model is a normative representation of that part of the Date/Time Vocabulary that can be conveniently represented in UML. The later text of 5.2 specifies the conventions used in creating the normative UML representation. They differ in some ways from the conventions presented in SBVR clause 13. That difference should be expressly stated in 5.2. The differences are primarily related to enabling effective formal specification of definitions and necessities in OCL.

The SBVR business vocabulary includes normative elements that are not represented in the UML model, typically because UML does not support Synonyms and Synonymous forms. That is the extent of the inferiority of the UML model. Any other discrepancy between the two models is an inconsistency in the specification.

SBVR SE is not a standard language and SBVR Annex C provides neither a grammar nor a formal interpretation for it. Formally, it is just a style that clarifies the use of English text. The formal forms of the Date/Time definitions and necessities are (incompletely) provided as OCL (and CLIF) formulations, that is, in standard languages with standard formal interpretations. Any discrepancy between the perceived meaning of the SBVR SE formulation and the OCL formulation may be an inconsistency in the specification, or just a misreading of the SBVR SE, but in any case the OCL formulation should take precedence – it is well-defined.

The FTF agrees that Clause 5 should specify that the DTV is structured as an SBVR Vocabulary and is intended to be interpreted into the SBVR XML form for a vocabulary as specified in Clause 15 of SBVR.
The FTF also agrees that the UML and OCL models are intended to be normative. Clause 5 will be modified to make this clear. In addition, clause 5 will be modified to reflect other corrections to the style of the UML and OCL models.
Editorial instruction 10 below, on OCL style, describes the current text, but may be amended by the resolution to Issue 16714.