There are a number of advantages gained by expressing business logic in business rules and using the processing and management facilities included with a Business Rules Management System to work with them.

• The separation of decision logic from mechanical implementation gives you more flexibility to make changes with minimal or zero impact on basic systems operation.
• Business rules are more understandable to business-level people, leading to better business/technical cooperation, reduced implementation times, and fewer opportunities for interpretation errors.
• Business rules are easily segmented into groups for control over functional interaction and management.
• Business Rules Management Systems have interactive testing, execution flow, cross-reference tools, and reporting features to aid in development, testing, and documentation.
• Business Rules Management Systems have predefined rule replacement features to handle system updates without interrupting service to application users.
• Business rules can have explicit times and dates when they should go into and out of effect.
• Rule management templates can be created to let users update, view, or create rules in a controlled manner without knowing anything about syntax or code.

Business rules syntax allows for a great deal of flexibility that you cannot replicate in traditional programming languages. Rules may be written with English phrases such as “If customer’s age exceeds 65 then set customer’s discount to .05”. This type of familiarity lets business policymakers work side by side with the implementation team. Indeed, many business analysts go through rule writing courses and then write rules with no previous programming experience.

The rule developer can also focus on the “correctness” of each atomic piece of logic instead of the sequencing and nesting of if-then-else constructs.

Business rules also provide flexibility for maintenance. In a traditional procedural implementation, the developer would have to understand the chaining programmed in the code for each if-then-else statement or loop. This is a time consuming and high-risk activity. Using rules, it is sufficient to replace, add or remove a rule. The next rule compilation will build a different decision structure that reflects the changes.

Rule templates give rule developers the ability to define specific structured types of rules or replaceable parts of existing rules that should be “exposed” to business level users for rule maintenance or creation. Business managers can make highly controlled and secure changes without ever seeing a word of the underlying rule syntax. Where appropriate, you can release the ownership of portions of the application business logic without running the risk of allowing unintended changes to other application code. This can greatly reduce costs in making incremental business changes to existing applications by taking the burden off programming departments having to work on maintenance releases.

Because the rules are managed and executed as an independent process called upon by your application, they can be updated at any time without requiring recompiles, links, or processing interruptions to your production application. Rule logic can be tested off-line and then introduced into a running application according to your strategy (scheduled, automatic or manual updates).

Related Briefs:

• What is a Business Rules Management System
• Decision Services Defined
• Business User Rule Maintenance