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

You've got a basic violation of Separation of Concerns/Single Responsibility Principle: Your business objects know about their storage.

The Data Layer of the 3-tier architecture should be responsible for CRUD operations, and should be queried for instances of the objects consumers need. Something like this:

Presentation Layer ------- Data Layer
                              ||
                              ||
                       Business Layer

This allows the business layer to focus on implementing, and keeps the persistence concerns out of it. If the Presentation layer needs a new business object (for creation), it asks the data layer for it.