A : You need to check the following points before implementing Rule engine in your project.
a) When business logic changes frequently: If your application has business logic which changes frequently, you should go for rule engine to maintain those rules/business logic.
b) Domain experts/ Business analysts are available but they are non technical : Here you have the right people for describing the business logic but they are not able to implement it technically. So you should go for rule engine to bridge the gap. In rule engine you don’t need to have technical knowledge to implement the business logic. So domain experts/ business analysts can implement it easily.
c) The business logic is complex : If your business logic is too complex and it does not fit in any traditional algorithm , you should go for rule engine.