Using XML with Legacy Business Applications

What Do We Need in a Solution?

When we ask, “What do we need?” we're talking about requirements. There are two types of requirements: functional and nonfunctional (the latter are also known as quality requirements or system constraints). The former have to do with what the system is supposed to do. The latter have to do with how it does what it does. Both are important, and both determine the overall approach of this book.

Beyond the overall dictate of solving the problem, two distinct sets of requirements are imposed on the solution by technical end users on the one hand and by application developers on the other. I'll talk a little later about why I'm dealing with both, but for now if you don't care about the other group you can just skip the ...