<p>eXtreme programming (XP) is one of a new breed of methods, collectively known as the agile methods, that are challenging conventional wisdom regarding systems development processes and practices. Practitioners specifically designed the agile methods to meet the business problems and challenges we face building software today. As such, these methods are receiving significant attention in practitioner literature. In order to operate effectively in the world of vague and changing requirements, XP moves the emphasis away from document-centric processes into practices that enable people. The Customer is the primary organisational facing role in eXtreme Programming (XP). The Customer's explicit responsibilities are to drive the project, providing project requirements (user stories) and quality control (acceptance testing). Unfortunately the customer must also shoulder a number of implicit responsibilities including liaison with external project stakeholders, especially project funders, clients, and end users, while maintaining the trust of both the development team and the wider business. This thesis presents a grounded theory of XP software development requirements elicitation, communication, and acceptance, which was guided by three major research questions. What is the experience of being an XP Customer? We found that teams agree that the on-site customer practice is a drastic improvement to the traditional document-centric approaches. Our results indicate, however, that the customers are consistently under pressure and commit long hours to the project in order to fulfil the customer role. So while this approach to requirements is achieving excellent results, it also appears to be unsustainable and thus constitutes a great risk to XP projects. Who is the XP Customer? The initial definition of XP resulted in many people interpreting the onsite customer to be a single person. This research has highlighted that a customer team always exists, and goes further to outline the ten different roles that were covered on the team, which range from the recognised "Acceptance Tester" role to the less recognised roles of "Political Advisor" and "Super-Secretary". What are the practices that support an XP Customer to perform their role effectively on a software development project? An additional eight customer-focused practices have been uncovered to supplement the existing XP practices. These customer-focused practices together enable customers to sustainably drive XP projects to successful completion. The practices range from those that specifically focus on interaction (both with the programmer team and the larger organisation) e.g. "Programmer On-site" and "Roadshows" to those that specifically look to the well-being and effectiveness of the customer (e.g. "Pair Customering") to those that highlight the key steps or activities that need to occur along the way (e.g. "Big Picture Up-Front" and "Recalibration").</p>
The Role of Customers in Extreme Programming Projects