From sun j2ee design pattern catalog, we can see the session facade should manage relationships between business objects and encapsulate the complexity of interactions between them. As seen from java petstore 1.1 sample, the example is: Customer(stateless session Facade)---> Account(entity) | ^ | | | | | | |---------------> Order (entity) So As I understand, Session facade is used to expose required interface to client, and client should not call entity directly. but the relationships between entity beans will not be affected when applying this pattern, is it right? What's your ideas about it? Any suggestions will be highly appreciated.