The concern of this book is how an organization's "information resource" may be identified, gathered, distributed, protected and controlled; in short, how information may be managed. Such information literacy requires a coherent set of concepts through which to understand information systems and a flexible methodology through which those concepts may be applied to any factual situation. It is the contention of this book that both of these may be provided by "soft" systems thinking. What is proposed is not simply another prescribed procedure for developing information systems, nor is it any way competitive with any existing development methodologies. Rather it is an approach to thinking about information systems (and their evolution through development methodologies) in relation to the organization which uses them. Thus well established techniques such as data modelling, though traditionally associated with the software engineering tradition, continue to be of great importance. It is aimed at students on computer science, management science, business sytems degree and MSc courses.