This book was written not only for those wishing to specialize in computer science but for the person who has an interest in the software development process whether as an accountant, manager or client. It follows the development of a system from the client's initial vague idea through a series of transitional stages to the completed software product. The process is illustrated throughout with a case study - the Just a Line Mail Order system. The authors try to combine theoretical and practical angles on both traditional structured analysis techniques with more recent approaches - such as CASE tools and formal notations.