On the Test-Driven Development and Validation of Business Rules

In recent years we have seen the rise of a new type of software called business rule management systems (BRMS). These are systems to externalize business rules and to provide a facility for centralized business rule management. This addresses an urgent need businesses do have nowadays: to change their business rules in order to adapt to a rapidly business environment, and to overcome the restricting nature of slow IT change cycles. Early manifestations of business rule engines which have their roots in the realm of artificial intelligence and inference systems were complex, expensive to run and maintain and not very business-user friendly. Improved technology providing enhanced usability, scalability and performance, as well as less costly maintenance and better understanding of the underlying inference systems makes the current generation of business rule engines (BRE) and rules technology more usable. However, there are a number of risks and difficulties that have to be taken into account when employing a BRMS. Another recent trend that tries to address the same problem of slow IT change cycles is agile software engineering, in particular test driven development. In this paper, we investigate how BRMSs can be used in conjunction with test driven development. The result is an approach that facilitates the authoring of business rules significantly and safeguards it by providing means for automated validation and verification.