The RuleSpeak® Business Rule Notation

Ronald G.  Ross
Ronald G. Ross Co-Founder & Principal, Business Rule Solutions, LLC , Executive Editor, Business Rules Journal , and Co-Chair, Building Business Capability (BBC) Read Author Bio       || Read All Articles by Ronald G. Ross
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).[1]  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[2] business rule notation developed by Business Rule Solutions, LLC (BRS) that has been used with business people in actual practice in large-scale projects since the second half of the 1990s. 

A companion column[3] 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[4] 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.[5]

Modal Operations in RuleSpeak

Behavioral

Modality claim type

Statement form

SBVR Structured
English keywords

RuleSpeak keywords

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

Definitional

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

Notes:

  • 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:
    1. an 'if' (yielding 'only if').
    2. 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
or  can
advice keyword

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.)

1.

 'Should' may be used in place of 'must' in expressing a business rule only if one of the following is true:

  • The business rule does not have an enforcement level.
  • The business rule has an enforcement level, and that enforcement level is consistent with the English sense of 'should'.

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:

  • The business rule has an enforcement level.
  • The enforcement level of the business rule is inconsistent with the English sense of 'should'.
2. 'May' must be used in the sense of 'permitted to' in RuleSpeak.  'May' must not be used in the sense of 'might'.[6]
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.  

Example:
  Rule:  A withdrawal from an account must not be made if the account is not active.
  Revised rule:  A withdrawal from an account may be made only if the account is active.

  Comment:  The revised rule is expressed in the form of a 'restricted permission statement'.

References

[1]  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/  return to article

[2]  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) 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). return to article

[3]  SBVR Excerpt, "Notations for Business Rule Expression," Business Rules Journal, Vol. 7, No. 4 (Apr.. 2006), URL:  http://www.BRCommunity.com/a2006/b286.html return to article

[4]  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). return to article

[5]  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. return to article

[6]  Principles of the Business Rule Approach, p. 130. return to article

# # #

Standard citation for this article:


citations icon
Ronald G. Ross , "The RuleSpeak® Business Rule Notation" Business Rules Journal Vol. 7, No. 4, (Apr. 2006)
URL: http://www.brcommunity.com/a2006/b282.html

About our Contributor:


Ronald  G. Ross
Ronald G. Ross Co-Founder & Principal, Business Rule Solutions, LLC , Executive Editor, Business Rules Journal , and Co-Chair, Building Business Capability (BBC)

Ronald G. Ross is Principal and Co-Founder of Business Rule Solutions, LLC, where he actively develops and applies the IPSpeak methodology including RuleSpeak®, DecisionSpeak and TableSpeak.

Ron is recognized internationally as the "father of business rules." He is the author of ten professional books including the groundbreaking first book on business rules The Business Rule Book in 1994. His newest are:


Ron serves as Executive Editor of BRCommunity.com and its flagship publication, Business Rules Journal. He is a sought-after speaker at conferences world-wide. More than 50,000 people have heard him speak; many more have attended his seminars and read his books.

Ron has served as Chair of the annual International Business Rules & Decisions Forum conference since 1997., now part of the Building Business Capability (BBC) conference where he serves as Co-Chair. He was a charter member of the Business Rules Group (BRG) in the 1980s, and an editor of its Business Motivation Model (BMM) standard and the Business Rules Manifesto. He is active in OMG standards development, with core involvement in SBVR.

Ron holds a BA from Rice University and an MS in information science from Illinois Institute of Technology. Find Ron's blog on http://www.brsolutions.com/category/blog/. For more information about Ron visit www.RonRoss.info. Tweets: @Ronald_G_Ross

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