what are the principles of the business rules approach ?

The Business Rules Approach (BRA) is a combination of existing and new techniques and technologies in order to identify the rules required to run a business, to document these rules, to reason with it, to make them operational in a consistent way, to systematically adapt it to ever changing market forces and to automate the enforcement of the rules where possible. The Business Rules Approach is based on the Zachman Framework to ensure a holistic enterprise view.

The principles of the Business Rules Approach are easily explained with the STEP-principle of Barbara von Halle:

Separation of the business rules from components that are not relevant to the business knowledge (mainly in IT systems).

Traceability of the business rules, i.e. documenting the sources as well as the usages of every of business rule.

Externalization of the business rules, i.e. making the business rules explicit.

Positioning of the business rules so that it becomes easily changeable and adaptable.