Bob,
>It looks like with the abstract class, I can allow the users to subclass and modify my business objects and then edit a table that the abstract class looks at to determine what class to use as the business object for that form?
>
>True?
>
>If so that's great... and hope it will work simmilarly in the 3-Tier implementation.
Sounds as if you have some very sophisticated users <bg>. You're right...as long as you have placed a record in the Abstract Factory's class lookup table your users (sounds more like developers) can change the entry in the table to use any class of their choosing...provided it has the same object interface.
Regards,
Kevin McNeish
Eight-Time .NET MVP
VFP and iOS Author, Speaker & Trainer
Oak Leaf Enterprises, Inc.
Chief Architect, MM Framework
http://www.oakleafsd.com