The technology for capturing and delivering business rules has, over the last 20 years, been given many "labels" including "Rule Based Systems", "Knowledge Based Systems" and "Expert Systems". These technologies share one basic design concept that of separating the business rules from the rest of the application running these rules. The business rules are maintained in a separate file which is run by a generic software component called the "Inference Engine".
Use of business Rules often results in time-to-production reductions of an order of magnitude or more, with a corresponding reduction in development costs. Business Rules have become very attractive for applications subject to frequent changes.