>When you design the BO, put code to validate the record before the save is committed. That way, no matter how many places can this save be called from, it will execute the same validation every time. Biz rules that are App specific I would not place in the SP of the DB, other validations that are not App specific for Ex. 'Sex' field accepting only 'M or F' can be enforced at the DB level.

Yes, but in what form are the BR's, class? method? various methods in a class? methods in the BO?

Thanks
Kev