2.3. Strong and Loose Coupling

Loose coupling involves "loosely" linking rules so that the execution of one rule will not lead to the execution of another.

Generally, a design exhibiting loose coupling is preferable because it allows for more flexibility. If the rules are all strongly coupled, they are likely to be inflexible. More significantly, it indicates that deploying a rule engine is overkill for the situation.

Strong coupling is a way of linking rules. If rules are strongly-coupled, it means executing one rule will directly result in the execution of another. In other words, there is a clear chain of logic. (A clear chain can be hard-coded, or implemented using a decision tree.)