The RuleSpeak® Business Rule Notation
In December 2007, the Object Management Group (OMG) approved the "Semantics of Business Vocabulary and Business Rules" (SBVR) to become an official specification of the OMG. Version 1 (SBVR 1.0) was published January 2008; Versions 2 (SBVR 1.1) & 3 (SBVR 1.2) were published in 2013). SBVR is the first OMG standard for concept models and business rules.
SBVR is a highly-structured set of fundamental concepts, not a syntax for rule representation. In part, this approach is necessary for multi-lingual support; in part, it is to ensure support for a variety of representational schemes. One such scheme is RuleSpeak®, which played a central role in the shaping and proofing of the standard itself. The material that follows is extracted from the RuleSpeak Annex of SBVR.
RuleSpeak® is an existing, well-documented business rule notation developed by Business Rule Solutions, LLC (BRS), which has been used with business people in actual practice in large-scale projects since the second half of the 1990s.
A companion column in this issue of the Journal introduced two styles of business rule statement: prefixed rule keyword style and embedded (mixfix) rule keyword style. That article detailed a business rule notation within SBVR Structured English that features prefixing rule keywords onto appropriate propositions. RuleSpeak can also use the expression forms of SBVR Structured English (term, name, and verb) but embeds equivalent keywords within the propositions themselves (mixfix). As the companion article explained, more than one notation for expressing business rules is possible using SBVR Structured English. (This is probably also true for other notations compliant with SBVR.) Regardless of how expressed, equivalent semantics can be captured and formally represented as logical formulations.
Expressions in RuleSpeak
RuleSpeak builds on the same expression forms described in the SBVR Structured English Annex of SBVR (Annex A), with the minor difference that distinct keywords are used for the Modal Operations related to business rules. The following section presents the RuleSpeak alternative rule keywords for Rules and Advices.
Modal Operations in RuleSpeak
Modality claim type
obligation claim obligation statement' it is obligatory that p r must s obligation claim embedding a logical negation prohibition statement it is prohibited that p r must not s restricted permission statement it is permitted that p only if q r may s only t permissibility claim unrestricted permission statement it is permitted that p r may s r need not s
necessity claim necessity statement it is necessary that p r always s necessity claim embedding a logical negation impossibility statement it is impossible that p r never s restricted possibility statement it is possible that p only if q r can s only t possibility claim unrestricted possibility statement it is possible that p r sometimes s r can s
- p and q, and r, s, and t, are all parts of the same proposition, say u.
- In a permissibility claim or a possibility claim, the 'only' is always followed immediately by one of the following:
- an 'if' (yielding 'only if').
- a preposition.
An example of a business rule statement using the 'only [preposition]' form is the following:
A spot discount for a rental may be given only by a branch manager.
Example in RuleSpeak
Each rental car must be owned by exactly one branch.
The example above includes three keywords, two terms (designations for noun concepts), and one verb symbol (of a verb concept's wording), as illustrated below.
As noted above, every Behavioral Business Rule or Advice can be stated by using one of the following embedded keywords.
must or should rule keyword must not or should not rule keyword only often as in only if rule keyword may or need not advice keyword
Every Definitional Rule or Advice can be stated by using one of the following embedded keywords.
always rule keyword never rule keyword can ... only often as in can ... only if rule keyword sometimes or not always
Special-purpose keywords for indicating specific kinds of Definitional Rules include the following. In these forms, 'always' is assumed implicit.
is to be considered for derivation or inference is to be computed as for computation is to be fixed at [number] or is to be [number] for establishing constants
Basic RuleSpeak Guidelines
Among the most basic usage rules and guidelines of RuleSpeak are the following. (Note that these usage rules and advices are given using proper RuleSpeak notation.)
'Should' may be used in place of 'must' in expressing a business rule only if one of the following is true:
To say this differently:
'Should' must not be used in place of 'must' in expressing a business rule if all of the following are true:
|2.||'May' must be used in the sense of 'permitted to' in RuleSpeak. 'May' must not be used in the sense of 'might'.|
|3.||An advice must not include a rule keyword.|
|4.||A statement expressing a rule or advice should
not begin with a condition.
Comment: 'Condition' as used here means a qualification set off by 'if', 'while', 'when', etc. (e.g., 'If a rental is open....').
|5.||A double negative should be avoided in
expressing a rule in RuleSpeak.
Comment: Double negatives, especially using two 'not's, are generally undesirable in good English usage and often prove particularly troublesome in rule statements.
Comment: The revised rule is expressed in the form of a 'restricted permission statement'.
 Semantics of Business Vocabulary and Business Rules (SBVR), v1.2. Object Management Group (Nov. 2013). SBVR 1.2 and its supporting files are available at http://www.omg.org/spec/SBVR/1.2/ The most-current version can always be found at http://www.omg.org/spec/SBVR/
 Ronald G. Ross. Principles of the Business Rule Approach. Boston, MA: Addison-Wesley, 2003, Chapters 8-12. Versions of RuleSpeak have been available on the Business Rule Solutions, LLC website (www.BRSolutions.com/b_principles.php) since the late 1990s. Public seminars have taught the syntax to thousands of professionals starting in 1996 (www.AttainingEdge.com). The original research commenced in 1985, and was published in The Business Rule Book, 1994 (www.BRSolutions.com).
 SBVR Insider, "Notations for Business Rule Expression," Business Rules Journal, Vol. 7, No. 4 (Apr. 2006), revised (Oct. 2013), URL: http://www.BRCommunity.com/a2006/b286.html
 For a business-oriented, SBVR-compliant approach, see: Ronald G. Ross. Business Rule Concepts: Getting to the Point of Knowledge. 4th ed.: Business Rule Solutions, LLC, 2013, Chapter 7. (www.BRSolutions.com/b_concepts.php).
 It is important to note that use of these keywords must be in a context that is clearly indicated to be for Rules and Advices only.
 Principles of the Business Rule Approach, p. 130.
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