Rule engine software is commonly provided as a component of a business rule management system which, among other functions, provides the ability to: register, define, classify, and manage all the rules, verify consistency of rules definitions, define the relationships between different rules, and relate some of these rules to IT applications that are affected or need to enforce one or more of the rules.
In any application, Business rules change more frequently than the rest of the application code. Rules engines or inference engines are the pluggable software components that execute business rules that have been externalized from application code as part of a business rules approach. This externalization of business rules allows the business users to modify the rules frequently without the need of IT intervention. The system as a whole becomes more adaptable with business rules that can be changed dynamically, although QAand other testing would still be required.