Planning on building business rules or automating your business decisions? Then, as part of your business analysis, you need a fact model. But what is this? How can you build one? Why should you significantly invest in building one as soon as you can and how will you recognise a good one when you have built it?

A fact model is a business oriented representation of your business’ key concepts and the facts that relate them. It is the enduring essence of your business, an alternative to an analysis domain model when business rules are the focus. A good fact model need not be complete, but it must accurately reflect the core nouns and verbs of your business.

How to Build a Fact Model

Creating a fact model requires some skill in business oriented information modelling and knowledge of: how to capture requirements (i.e., mine terms, facts and rules) from existing sources; how to discover terms, facts and rules from new sources (while continuously judging and assuring their quality) and how to document all these effectively and with minimal cost. Fortunately, some external consultancies offer a high degree of expertise in this field; some even offer business-specific experience. There are also standards (see Ronald G Ross Business Rule Concepts) governing how fact models can be captured and free tools (like RuleArts FactXpress) to help you.

So why take the trouble to do all this? Haven’t you managed perfectly well without a fact model for so many years? So why should you make this considerable investment? Well, forming a fact model of your business not only produces a highly valuable and durable asset with many uses, it is a beneficial exercise in itself and often yields new business insights and opportunities.

Furthermore you will need one if:

  • You want your business rules to be precise, clear, consistent, complete and reusable
  • You ever intend people, outside of your development team, to understand, review or even amend business rules developed by that team or a messaging standard introduced by that team
  • You wish the invaluable knowledge that expert SMEs carry in their head, which they took years to amass, to survive their departure from your company
  • You would like to bring new trainees up to speed with your business quickly
  • You would like to simplify and consolidate the concepts and structures of your business as they have grown overly complex over time or as the result of a merger

Evaluating a Fact Model

Here’s how you tell if you have a good fact model:

  • it will not be seriously perturbed by new modes of doing business, or additions (indeed it may evensuggest them)
  • it focuses on true business terms and is not corrupted by technical terminology or artefacts associated with how the business policy is currently implemented (e.g. with reference to existing systems or technical jargon), thereby ensuring that any artefact expressed in terms of the fact model remains a business asset, under business control
  • it describes your business without constraining its growth or flexibility. That is it does not make implicit assumptions about current business practices that may change in future. The fact model should not feature any business constraints at all, it is the job of rules to provide these. Ross’s analogy of the human body is effective here: in order to be agile a body needs a good, firm skeleton (the fact model). It should be strong, but not limit movement unnecessarily. The rules (the central nervous system of the body) can then constrain and control it by governing the muscles (business processes).


Good tools now exist to administer and support the collaborative development of fact models – so now there is no excuse. Go out and start work on your business fact model as a matter of urgency.

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