We had similar question with us, we finally picked up Drools, one should use drools if you have following:
- Business logic which you think is getting cluttered with multiple if conditions because of variety of scenarios
- You will have growing demand of increase in the complexity
- The business logic changes would be frequent (1 - 2 times a year would also be frequent)
- Your server's have enough of memory as it is a memory hungry tool, it provides performance at cost of memory
Have more details at following URL
