Semantics of Business Vocabulary and Business Rules - Fact-orientation

Fact-orientation

People communicate facts, that is the fact is the unit of communication. The fact-oriented approach enables multidimensional categorization.

• The fact-oriented approach supports time changeability.
• The fact-oriented approach provides semantic stability.
• The fact-oriented approach enables extensibility and reuse.
• The fact-oriented approach involves breaking down compound fact types into elementary (atomic) ones.

Conceptual formalization describes a business domain, and is composed of 1) a conceptual schema (fact structure) and 2) a population of ground facts. A business domain (universe of discourse) comprises those aspects of the business that are of interest.

The schema declares:

• the relevant fact types (kinds of ground fact, e.g. Employee works for Department)
• the relevant business rules (typically constraints or derivation rules).

A fact is a proposition taken to be true by the business. Population facts are restricted to elementary and existential facts.

Constraints can be static or dynamic:

• A static constraint imposes a restriction on what fact populations are possible or permitted, for each fact population taken individually e.g. Each Employee was born on at most one Date.
• A dynamic constraint imposes a restriction on transitions between fact populations

e.g. a person’s marital status may change from single to married, but not from divorced to single

Derivation of facts.

• Derivation means either, how a fact type may be derived from one or more other fact types e.g.
  • Person1 is an uncle of Person2 if Person1 is a brother of some Person3 who is a parent of Person2
• Or, how a noun concept (object type) may be defined in terms of other object types and fact types e.g.
  • Each FemaleAustralian is a Person who was born in Country ‘Australia’ and has Gender ‘Female’