N-Tier Architecture - Structure with multiple projects in VB.NET

Question

I would like some advice on the best approach to use in the following situation...

I will have a Windows Application and a Web Application (presentation layers), these w

Answer 1

Your general approach is sound :)

You could consider putting all the interfaces in a seperate assembly (dll) (strictly speaking the interface sits between the business logic and the data access implementation - they should be the only things that have access to the interface), but in the grand scheme of things that might not be such a big deal.

Personally I'd have one shared factory method that returned an object, and just cast it appropriately when used.