The Production Rule Representation (PRR) is a proposed standard of the Object Management Group

Object Management Group

Object Management Group is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling and model-based standards.- Overview :...

 (OMG) to provide a vendor-neutral rule-model representation in UML

Unified Modeling Language

Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

 for production rule

Production rule

Production rule may refer to:*For production rules used in business rule engines, cognitive modeling and artificial intelligence, see production system*For production rules that expand nodes in formal grammars, see formal grammar-See also:...

s as used in forward-chaining rule engines.

History

The OMG set up a Business Rules Working Group in 2002 as the first standards body to recognize the importance of the "Business Rules Approach

Business rules approach

Business rules are abstractions of the policies and practices of a business organization. The Business Rules Approach is a development methodology where rules are in a form that is used by, but does not have to be embedded in, business process management systems.The Business Rules Approach...

". It issued 2 main RFPs in 2003 – a standard for modeling production rules (PRR), and a standard for modeling business rules as business documentation (BSBR, now SBVR

Semantics of Business Vocabulary and Business Rules

The Semantics of Business Vocabulary and Business Rules is an adopted standard of the Object Management Group intended to be the basis for formal and detailed natural language declarative description of a complex entity, such as a business...

).

PRR was mostly defined by and for vendors of Business Rule Engines (BREs) (sometimes termed Business Rules Engine

Business rules engine

A business rules engine is a software system that executes one or more business rules in a runtime production environment. The rules might come from legal regulation , company policy , or other sources...

(s), like in Wikipedia). Contributors have included all the major BRE vendors, members of RuleML

RuleML

The Rule Markup Language is a markup language developed to express both forward and backward rules in XML for deduction, rewriting, and further inferential-transformational tasks...

, and leading UML vendors.

Evolution

1. The PRR RFP originally suggested that PRR use a combination of UML OCL
   Object Constraint Language
   The Object Constraint Language is a declarative language for describing rules that apply to Unified Modeling Language models developed at IBM and now part of the UML standard. Initially, OCL was only a formal specification language extension to UML. OCL may now be used with any Meta-Object...
   
    and Action Semantics for rule conditions and actions. However, expecting modellers to learn 2 relatively obscure UML languages in order to define a production rule proved unpalatable. Therefore PRR OCL was defined that included OCL extensions for simple rule actions (as well as external functions). PRR OCL is currently considered "non-normative" i.e. is not part of the PRR standard per se. PRR beta applies just to a PRR Core that excludes an explicit expression language.
2. The PRR RFP envisaged covering both forward and backward chaining rule engines. However, the lack of vendor support for / interest in backward chaining caused this to be revise to forward chaining and "sequential" semantics. The latter is simply the scripting mode provided by many BPM tools, where rules are listed and executed sequentially as if programmed. This provides PRR with better compatibility with typical BPM scripting engines (and acknowledges the fact that most BREs today support a "sequential" mode of operation, improving performance in some circumstances).

Status

PRR is currently at version 1.0. Per the OMG process it is currently being revised by a Revision Task Force expecting to release a 1.1 version in 2010. Revision task force members were ILOG

ILOG

ILOG is an international software company owned by IBM. It creates enterprise software products for supply chain, business rule management, visualization and optimization....

 Inc (co-chair), NoMagic Inc, TIBCO Software

TIBCO Software

TIBCO Software Inc. is a provider of infrastructure software for companies to use on-premise or as part of cloud computing environments. TIBCO manages information, decisions, processes and applications in real-time for over 4,000 customers worldwide...

 Inc, Business Semantics Ltd, Inferware LLC, Sandpiper Software Inc, and 88 Solutions Inc.

See also

• Production system
  Production system
  A production system is a computer program typically used to provide some form of artificial intelligence, which consists primarily of a set of rules about behavior. These rules, termed productions, are a basic representation found useful in automated planning, expert systems and action selection...
  
   which describes the typical rule engine that executes production rules
• Business Rule Management System which would typically define the business user interface for production rules.
• Rule Interchange Format
  Rule Interchange Format
  The Rule Interchange Format is a W3C Recommendation. RIF is part of the infrastructure for the semantic web, along with SPARQL, RDF and OWL...
  
   by W3C especially its Production Rule Dialect, which is nominally compatible with the PRR metamodel.
• Ripple down rules
  Ripple down rules
  Ripple Down Rules is a way of approaching knowledge acquisition. Knowledge acquisition refers to the transfer knowledge from human experts to knowledge based systems.- Introductory material :...
  
  

Sources

1. OMG Press Release on PRR Adoption Dec 2007
2. OMG Specification page