Before You Start
Many traditional systems-development lifecycles start with a requirements definition or marketing analysis phase. This phase probably has already been completed by the time someone talks with you about XML. You'll probably be presented with some high-level requirements for enabling the application to produce or consume XML documents. If you're lucky, you'll get a chance to do some preliminary analysis and design work before you're asked those all-important questions: How much will it cost? and How long will it take? We'll start by assuming that you've been given a fairly broad set of requirements, such as producing purchase orders in XML, or creating a web services interface for an order-management application. The goal of the first phase is to nail down the specific requirements.