1. Oakkar Fall 2010

2. The Need for Decision Engine Automate business processes Implement complex business decision logic Separation of rules and process Business Requirements Vs. Algorithm

3. Problems Processes and decisions are not well represented in traditional programming language like C# or Java Enterprise systems usually have multiple layers Presentation Business Logic <- constantly evolving Data Code becomes overwhelmingly complex and hard to maintain Nested if-else, switch, for, while Change something and break something else

5. Drools Business Rules Engine + Expert System Products Drools Expert (Rule Engine) Drools Guvnor (BRMS/BPMS) Drools Flow (Process/Workflow) Drools Fusion (Event processing/temporal reasoning) Drools Planner

6. Drools Expert Development Platform Rules Decision Tables Rule Templates Domain Specific Language

7. Drools Guvnor Business Rules Management System Web-based interface Integration Issues

9. Advantages Easier to understand Improved Maintainability Deals with evolving complexity Flexibility Reasonable Performance Reusability Requirements can be naturally translated into rules

10. Disadvantages Hard to debug Memory consumption Interaction of rules can be very complicated

11. When not use a rule engine Small project less than 20 rules Business Logic is well defined and static If your business rules are simple High performance is your primary Limited resources