Can You Violate Structural Rules? (Part 1) ~ The Difference Between Violations and Bad Decisions

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

This issue's column is another installment of my periodic 'notepad' series, which focuses on specific issues facing practitioners seeking to understand business rules and make them part of their company's approach to requirements and system development.

Let's put the following business rule under the microscope:  A gold customer must be allowed access to the warehouse.   Clearly this rule can be violated.  If a gold customer is denied access to the warehouse (assuming there are no extenuating circumstances, such as exception rules), then a violation has occurred.  Presumably, there is a sanction associated with such violation -- for example, the security guard might be called on the carpet.  Any rule that can be violated in that sense is an operative rule.

Note that there are additional rules bearing on evaluation of the warehouse rule.  Specifically, what criteria are appropriate for determining whether a particular customer is 'gold' or not?  Such rules are called structural rules.

If a Customer appears at the warehouse, but the security guard is unaware of such criteria, misapplies them, or uses the wrong ones, quite possibly the Customer will not be given due access.  The error, however, manifests itself in the form of a violation of the operative rule, not the structural rule(s) per se.  Structural rules can be ill formed or misapplied, but they cannot be directly violated.

This is a significant difference between operative rules and structural rules.  To re-iterate, disregard for operative rules leads to violations and possible sanctions; misapplication of structural rules leads to mistakes and undesirable results -- but only indirectly, if at all, to violations.

It would seem then that structural rules, in contrast to operative rules, are more 'definitional' in nature.  In a general sense, that is true.  However, in practice a clear distinction nonetheless can and should be maintained between definitions and structural rules.  Specifically, a definition should focus on the essence of a concept -- its meaning to the business -- whereas structural rules should indicate exact lines of demarcation.  Consider an 'essence' definition of Gold Customer as compared to an associated structural rule:

Defining Statement:  A Gold Customer is a Customer that does a significant amount of business over a sustained period of time.

Structural Rule:  A Customer must be considered Gold Customer if the Customer places more than 12 orders in a calendar year.

The definition provides a clear idea about what 'Gold Customer' means to the business.  It is unlikely that basic notion will change -- in other words, the notion as defined in the manner above is very stable.  The structural rule, in contrast, gives specific criteria for determining whether a Customer is or is not 'Gold' -- criteria that quite possibly will change over time.

Another difference between definitions and structural rules is that the latter frequently give criteria that would not be obvious given the definition.  Here is an example:

Structural Rule:  A Customer may be considered a Gold Customer only if the Customer was incorporated more than a year ago.

Incidentally, this rule -- although not in the form of an 'if-then' statement -- is actually an inference rule.  Indeed, inference rules are structural, rather than operative.

A complex decision point may involve hundreds or even thousands of inference rules.  Their application and evaluation, however -- no matter how many rules are involved -- cannot directly result in a violation.  Although the result might be quite serious for the business -- perhaps even calamitous -- technically, no violation has occurred.  The result would simply represent a really, really bad decision.

Part 2 of this three-part series will examine rules for mathematical computation, applying the same criteria as above to determine whether they are operative or structural.

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Standard citation for this article:

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Ronald G. Ross, "Can You Violate Structural Rules? (Part 1) ~ The Difference Between Violations and Bad Decisions" Business Rules Journal, Vol. 6, No. 2, (Feb. 2005)

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 BRS 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 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 For more information about Ron visit Tweets: @Ronald_G_Ross

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