Few would disagree that striving for a loosely coupled design is a bad thing. Unfortunately, the software we typically design is much more tightly coupled than we intend. How can you tell whether your design is tightly coupled? You can use a static analysis tool like NDepend to analyze your dependencies, but the easiest way to get a sense of the coupling in your application is to try to instantiate one of your classes in isolation.Pick a class from your business layer, such as an InvoiceService, and just copy its code into a new console project.
