science

Production Rule Representation

Production Rule Representation is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Production Rule Representation rather than just read about it. In short: The Production Rule Representation (PRR) is a proposed standard of the Object Management Group (OMG) that aims to define a vendor-neutral model for representing production rules within the Unified Modeling Language (UML), specifically for use 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 A…

Key takeaways

Production Rule Representation belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Production Rule Representation to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Production Rule Representation from memory before moving on to harder problems.

Reference excerpt

The Production Rule Representation (PRR) is a proposed standard of the Object Management Group (OMG) that aims to define a vendor-neutral model for representing production rules within the Unified Modeling Language (UML), specifically for use 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". 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). PRR was mostly defined by and for vendors of Business Rule Engines (BREs) (sometimes termed Business Rules Engine(s), like in Wikipedia). Contributors have included all the major BRE vendors, members of RuleML, and leading UML vendors.

Evolution The PRR RFP originally suggested that PRR use a combination of UML OCL 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. 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.

See also Decision Model and Notation a standard for modeling decisions and decision tables suitable for execution in business rule management systems Production system 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 by W3C especially its Production Rule Dialect, which is nominally compatible with the PRR metamodel. Ripple down rules

Sources OMG Press Release on PRR Adoption Dec 2007 OMG Specification page

Worked examples

Example 1 — a first encounter with Production Rule Representation

Start with the simplest possible case. Write down what Production Rule Representation claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Production Rule Representation before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Production Rule Representation ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Production Rule Representation

In research: Production Rule Representation appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Production Rule Representation in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Production Rule Representation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Knowledge representation languages, Rule engines, Unified Modeling Language, so understanding it makes those chapters shorter.
In everyday life: Look for Production Rule Representation outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Production Rule Representation in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Production Rule Representation means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Production Rule Representation out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Production Rule Representation in simple terms?

Why does Production Rule Representation matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Production Rule Representation?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Production Rule Representation.