A new version 1.4 of SBVR was published by Object Management Group in May 2017 after 2 years of work and debate. You can download it from http://www.omg.org/spec/SBVR/ (free download and you don’t need to register).
How is SBVR 1.4 different from previous versions of SBVR?
To answer this question, let’s separate the formal core of SBVR from its more accidental explanatory and presentational aspects.
We can do that because SBVR is itself an SBVR specification. It presents a semantic model by presenting a terminological dictionary and a rulebook in a structured format of terminological entries. These formal entries, the core of the specification, are surrounded by other document elements that are less formal, more explanatory: introductory texts; a structure of chapter headings and clause headings; diagrams and annexes.
The committee members responsible for the upgrade to SBVR 1.4 have chosen to change the explanation and presentation of SBVR quite considerably, while at the same time leaving the formal core of the specification largely intact. If you are a newcomer to SBVR, you should find it easier to find your way in SBVR 1.4 than in previous versions. If you are a seasoned user of SBVR, you do not need in-depth study to become familiar with the new version.
The Table of Contents of the SBVR 1.4 document looks quite different from earlier versions. The structure, naming and numbering of clauses and subclauses has completely changed. The formal entries, whilst largely the same as before, have all found a different place in this new arrangement.
The leading idea seems to have been to introduce an overarching architecture. Early versions of SBVR already referred to Peirce’s famous Semiotic Triangle, which invites you to distinguish 3 closely related aspects of each element in an SBVR model (such as a business term): its expression, its meaning, and the things in reality that it refers to. But the Semiotic Triangle used to be tucked away in a subclause about relating meaning to extension. In SBVR 1.4, it has become the guiding structural principle for the specification. For newcomers, this creates a mental map: it makes it easier to understand and memorise “where each piece belongs”.
A largely unchanged specification
As for the formal core of the specification, many small errors have been fixed and definitions have been refined. These improvements represent a tremendous amount of work on the part of the members of the authoring committee and as a community we must be grateful for their contributions. At the same time, those already familiar with SBVR will find few fundamental changes.
Just as a single example (among the very many) of the kind of refinement typical of the upgrade to SBVR 1.4, the definition of the key term of ‘business rule’ is now:
Definition: Rule that is practicable and that is under business jurisdiction
where in pre-1.4 versions of SBVR it used to be:
Definition: Rule that is under business jurisdiction
In other words, for a rule to qualify as a business rule it is no longer sufficient that it is under business jurisdiction. It must also be practicable. What that means is formally described by SBVR, because each rule is an element of guidance, and SBVR also has the definition:
element of guidance is practicable
Definition: The element of guidance is sufficiently detailed and precise that a person who knows the element of guidance can apply it effectively and consistently in relevant circumstances to know what behavior is acceptable or not, or how something is understood.
This idea of practicability has always been fundamental to SBVR. Since the beginnings, it has played an important role in distinguishing business policies from business rules: a policy is an important general guideline for an organisation but by itself, it is not precise enough to tell operators what to do in a given situation, or to tell auditors whether or not it has been violated in a given situation, and that is why the organisation needs rules and not just policies.
What has changed is that the 1.4 definition of business rule now requires a rule to have this kind of practicability to qualify as a business rule in the first place. That was always the spirit of the idea, but the earlier definitions of business rule did not state it.
This change is a welcome refinement and eases understanding. But it is fair to say that the core specification has remained unaltered.
For die-hards who have already ventured into this area, let me add that this is further illustrated by the fact that all the definitions in the surrounding structure of concepts are the same in SBVR 1.4 as in previous versions. This applies in particular to ‘element of guidance is practicable’ and ‘element of governance is directly enforceable’. It has always been the case in SBVR that an ‘element of governance’ is an ‘element of guidance’ considered in the light of its being directly enforceable or not, and that a business policy is distinguished by its not being directly enforceable, and that each element of governance that is directly enforceable is by definition practicable.