A Business Rules Engine (BRE) is software that allows programmers to add or change business logic within a Business Process Management (BPM) system. A business rule can describe a policy or a procedure and business logic is the sequence of operations associated with the data within a database to carry out that rule.

A business rule engine can separate business rules from a business process management system enabling users to change a business rule without relying on a programmer to do it for them. The engine will then examine the effect of the new rule on the system and highlight any conflicts.