Ok that makes sense. But are not the BO's specific to an app?

I always used the BO's not only to pass data to & fro, but to
enforce rules that belong to the app.



>At the risk of repeating what Bonnie said, yes, definitely keep them separate.
>
>You may later find yourself needing some of the classes in your business layer for other client projects - so keeping them separate now will help down the road. By designing these assemblies to work through an interface/protocol (as opposed to an implementation), that will give you flexibility later.
>
>Kevin