Version 1.0 of OMG's formal specification "Semantics of Business Vocabulary and Business Rules" (SBVR) appeared in January 2008.  SBVR has recently been evolving:  Version 1.1 was published in September 2013 and Version 1.2 in November 2013.

How did it change?  It's an interesting question, especially of course for those who have done work on the basis of the original SBVR 1.0 but have not found the time to dive into the more recent versions.  More generally, looking at changes in SBVR provides an insight into the concerns of the OMG committee responsible for the specification.

This article shows how SBVR changed by summarizing the conceptual changes in SBVR's key Clause 8, which covers its Meaning and Representation Vocabulary.^[1]  According to this clause, business meaning is embodied in noun concepts, verb concepts, questions, and propositions. 

In Clause 8, changes have occurred in three areas:

• 'Object type' was replaced with 'general concept'.
• 'Fact type' (and related concepts) was replaced with 'verb concept'.
• Unitary concepts were introduced.

The easiest way to visualize the changes is to reproduce diagram fragments^[2] from the respective SBVR versions.  SBVR 1.0 contained the diagram fragment shown in Figure 1.

Figure 1.  Meaning and Representation Vocabulary Clause 8.1 Diagram, SBVR 1.0 

SBVR 1.1 contained the diagram fragment shown in Figure 2.  Changes relative to the previous version are in bold.

Figure 2.  Meaning and Representation Vocabulary Clause 8.1 Diagram, SBVR 1.1 

SBVR 1.2 contains the following diagram fragment shown in Figure 3.

Figure 3.  Meaning and Representation Vocabulary Clause 8.1 Diagram, SBVR 1.2 

'Object type' was replaced with 'general concept'

'Object type' was a key concept in SBVR 1.0, defined as:

object type
	Definition:	noun concept that classifies things on the basis of their common properties
		(SBVR 1.0, 8.1.1)

The 8.1 diagram shown in Figure 1 mentioned 'general concept' as a synonym of 'object type', but general concept was not formally declared as being part of the Meaning and Representation Vocabulary in SBVR 1.0.  In SBVR 1.1 and 1.2, 'object type' has been dropped and 'general concept' has taken its place, defined as:

general concept
	Definition:	noun concept that classifies things on the basis of their common properties
		(SBVR 1.2, 8.1.1)

Somewhat confusingly, in 'SBVR-style' glossary documents since the original 1.0, it has been common practice to use the phrase "General Concept:" as a left-hand caption, indicating what is technically in SBVR the more general concept of the concept being described.  (This is also sometimes — but not in SBVR — referred to as the 'supertype'.) 

This practice is also apparent in the SBVR specification itself, e.g.:

concept
	General Concept:	meaning
		(SBVR 1.2, 8.2.1)

'Fact type' (and related concepts) was replaced with 'verb concept'

SBVR 1.1 saw the replacement of fact type — a term from logic — with verb concept, a term from linguistics.  As a corollary, fact type form was replaced with verb concept wording:^[3]  Table 1 provides an overview of the changes.

Table 1.  The evolution of 'fact type' concept terms.

SBVR 1.0	SBVR 1.1	SBVR 1.2
fact type role	verb concept role	verb concept role
fact type	verb concept	verb concept
binary fact type	binary verb concept	binary verb concept
fact type has role	verb concept has role	verb concept has role
fact type form	verb concept wording	verb concept wording
fact type has fact type form	verb concept has verb concept wording	verb concept has verb concept wording
fact type form demonstrates designation	verb concept wording demonstrates designation	verb concept wording demonstrates designation
fact type form has placeholder	verb concept wording has placeholder	verb concept wording has placeholder

While this has largely been a rename operation, the definition of the concept has also shifted from each version to the next, as follows:

fact type
	Definition:	concept that is the meaning of a verb phrase that involves one or more noun concepts and whose instances are all actualities
		(SBVR 1.0, 8.1.1)

 

verb concept
	Definition:	concept that specializes the concept 'actuality' and that is the meaning of a verb phrase that involves one or more roles
		(SBVR 1.1, 8.1.1)

 

verb concept
	Definition:	concept that specializes the concept 'state of affairs' and that is the meaning of a verb phrase that involves one or more verb concept roles
		(SBVR 1.2, 8.1.1)

The change between 1.1 and 1.2 (from actuality to state of affairs) was a necessary correction.  In SBVR, a 'state of affairs' is any event, activity, situation, or circumstance; an 'actuality' is a state of affairs that actually happens, takes place, obtains.  The 1.2 definition of verb concept is the correct one because it is possible for a verb concept to have an instance that is a state of affairs but not an actuality.  The concept represented by the expression "John Merriman works for JellyFish" may correspond to an 'actuality' (in which case it is a proposition said to be true), or it may merely correspond to a 'state of affairs' that is not actual.  Even in the latter case, it's still an instance of the verb concept 'person works for organization'.

SBVR 1.2 reveals a preoccupation with the relationship between verb concepts and what they correspond to in business reality.  Two new notes were added to the entry for verb concept.  They explain the relationship between a verb concept and its instance(s) in logical and linguistic terms, respectively:

	Note:	A propositional function becomes a proposition when it is closed; it is closed by binding it to a logical constant (an individual noun concept) or a quantified variable (that ranges over some possibly qualified noun concept).
	Note:	A verb concept role is played by a thing in the domain of discourse - the world of interest. A verb concept is 'bound' by specifying the thing(s) that play the verb concept role. Linguistically those things can be specified by a quantified noun phrase or by an individual noun concept or by a pronoun that refers to a specific thing.
		(SBVR 1.2, 8.1.1, 'verb concept')

Unitary concepts

The recent versions of SBVR introduce unitary concepts.  SBVR had always distinguished a special kind of noun concept called 'individual concept', as follows:

individual concept
	Definition:	concept that corresponds to only one object [thing]
	Example:	The individual concept 'California' whose instance is an individual state in the United States of America.
		(SBVR 1.0, 8.1.1)

In SBVR 1.1, this model was refined by the introduction of unitary concept:

unitary concept
	Definition:	individual concept or general concept that always has at most one instance
		(SBVR 1.1, 8.1.1 )

A note added to the 1.1 entry for individual concept helped make the difference:

Note:

Individual concepts are unitary concepts whose extensions are necessarily invariant across all possible worlds.

Also, subclause 8.5.2 contains the following definitional rule:

Necessity:

Each individual concept that corresponds to a thing always corresponds to that thing.

Here, 'always' means 'in all possible worlds'.  For example, 'Barack Obama' is an individual concept because it corresponds to the same person in any world of interest, whereas 'The President' is a unitary concept because it corresponds to at most one person at any one time but potentially to different persons in different worlds of interest (which would be, in this case, different periods in history).^[4]

In SBVR 1.2, the definition of 'unitary concept', and of its new synonym 'unitary noun concept', was revised to:

unitary noun concept
	Definition:	noun concept that corresponds to at most one thing at a time
		(SBVR 1.2, 8.1.1 )

The synonym 'unitary noun concept' was called for because SBVR 1.2 extends the idea of 'unitariness' to verb concepts.  A unitary verb concept has exactly one instance in a given possible world at a given time.  As an example, SBVR 1.2 gives the verb concept 'the consolidated global account is filed in the base currency in the compliant format'.  What makes this concept unitary is that 'consolidated global account', 'base currency', and 'compliant format' each refer to only one object.  (As it happens, in this case, this is implied in the language form by the use of the definite article 'the' for each; a possible extension in one world of interest at one time could be 'the consolidated global account is filed in Swiss Francs in XBRL'.)

The Semiotic Triangle

SBVR 1.2 introduces the Semiotic Triangle as an explanatory framework by inserting the picture "Relating Meaning to Extension" in subclause 8.6.1.  This picture shows a triangle formed by three basic noun concepts and the three verb concepts that connect them.  Figure 4 is a simplified version of this picture.

Figure 4. The Semiotic Triangle

Here are the SBVR 1.2 definitions of the concepts depicted:

meaning
	Definition:	what is meant by a word, sign, statement, or description; what someone intends to express or what someone understands
		(SBVR 1.2, 8.2)

 

thing
	Definition:	anything perceivable or conceivable
		(SBVR 1.2, 8.7)

 

expression
	Definition:	something that expresses or communicates, but considered independently of its interpretation
		(SBVR 1.2, 8.3)

 

meaning corresponds to thing
	Definition:	the thing is conceptualized by and is consistent with the meaning
	Note:	A concept corresponds to each instance of the concept. A proposition corresponds to a state of affairs (which might or might not be actual). A proposition that is true corresponds to an actuality.
		(SBVR 1.2, 8.6.1)

 

expression represents meaning
	Definition:	the expression portrays or signifies the meaning
		(SBVR 1.2, 8.4)

The verb concept expression denotes thing, while a basic concept in the Semiotic Triangle picture, is not formally declared in the SBVR metamodel.  In some places in the specification, the verb 'denote' is informally used to explain notions of representation (i.e., the expression–meaning relationship), as follows [emphasis added]:

designation
	Definition:	representation of a concept by a sign which denotes it
		(SBVR 1.2, 8.4.1)

In other places, 'denote' is used to explain notions of denotation (i.e., the expression–thing relationship), as follows [emphasis added]:

state of affairs
	Note:	Any representation of a proposition may be used to denote the state(s) of affairs that it corresponds to. (…)
		(SBVR 1.2, 8.6)

In this note, in terms of the Semiotic Triangle as well as in SBVR itself, 'representation' refers to an expression, 'proposition' to a meaning, and 'state of affairs' to a thing.

The Semiotic Triangle picture is presented in subclause 8.6.1, which is entitled "Relating Meaning to Extension."  This placement is somewhat arbitrary, even if the accompanying text does clearly state that 8.6.1 is about "one leg" of the triangle.  In reality, the Semiotic Triangle is an excellent mental map for grasping the whole of SBVR's Clause 8, that is, the SBVR metamodel on Meaning and Representation.

Conclusions

In Clause 8, the Meaning and Representation Vocabulary of OMG's SBVR specification, the following points summarize the main changes from SBVR 1.0 through SBVR 1.2:

• Key concepts have been evolving slightly in 2013 but show great stability overall.  In particular, the concept structure is almost identical to what it was in 2008.
  
  
• There is a slight shift from logical and object-oriented terminology ('fact type', 'object type') to terms of a more semiotic or linguistic inspiration ('verb concept', 'general noun concept').
  
  
• The way in which verb concepts correspond to states of affairs is accounted for with greater precision.

References

[1]  This article is based on a detailed comparison of changes between the 1.0, 1.1, and 1.2 specifications of SBVR.  It is strictly limited to Clause 8.  If you are interested in revisions to other Clauses, note that OMG provides document versions with changebars.  These make it easier to compare versions.  You may also want to consider automating version comparison by feeding the XMI machine-consumable versions of the specification into a software tool.  However, making sense of the revisions and the multiple interdependencies between changing concepts remains a manual process.  I have tried to refrain from personal interpretation and commentary.  Inevitably, the act of summarizing this material implies some degree of interpretation.

All the quotations in this article are literal quotations from the official documents as published on the OMG website, including any color-coding of text.  In many cases, however, only a subset of the items in a glossary entry was quoted.  If a glossary entry in this article contains one "Definition:" and one "Note:" item, it is quite possible that in the SBVR specification it contains other items not quoted, with the same or different captions (Example, Source, General Concept, etc.).  

[2]  Diagram fragments:  in spite of what 'fragment' suggests, I ended up copying the 8.1 diagrams almost in their entirety.  I omitted some details that I think distract from the discussion at hand, in particular, 'concept type' as a specialization of 'general concept'.  Again, whatever diagram fragments were copied in this article appear identically in the OMG documents.  

[3]  The change is more subtle than summarized here.  SBVR 1.0 already mentioned 'verb concept' as a possible alternative for 'fact type'.  However, in 1.0, 'fact type' was the more common term and also the term used to derive other related concepts, like 'fact type form'.  'Fact type' is still a declared concept of the SBVR 1.2 metamodel, but it has been moved to Clause 10 (the part of the SBVR metamodel called Formal Logic and Mathematics Vocabulary) and thereby outside the scope of this article.  The section on Conceptual Models and Schemas was also moved from Clause 8 to Clause 10.  

[4]  Or, more precisely, the concept that the two words 'Barack Obama' are usually taken to represent is an individual concept; the concept that the two words 'The President' are usually taken to represent is a unitary concept.  

# # #