Creating A Loosely-Coupled / Scalable software architecture

Question

I\'ve been researching this for weeks. I\'m currently designing a loosely-coupled architecture design using n-tier (3-layered) method and factory design ap

Answer 1

The only thing I see, and I mist just be missing this in looking at your post, but I don't see a DAL interface definition or abstraction layer that seperates it from your BL in the way your BL is abstracted from your presentation.

This is important because it gives you the flexibility in the future to create a new business layer using the same data without having to rewrite the DAL, or replacing your database with flat CSV files/mocks in unit testing/a 3rd party maintained soap web service response, or whatever else might be a better data storage mechanism in the future.