Requirements engineering is the process of discovering, documenting and managing the requirements for a computer-based system. The goal of requirements engineering is to produce a set of system requirements which, as far as possible, is complete, consistent, relevant and reflects what the customer actually wants. Although this ideal is probably unattainable, the use of a systematic approach based on engineering principles leads to better requirements than the informal approach which is still commonly used. This book presents a set of guidelines which reflect the best practice in requirements engineering. Based on the authors' experience in research and in software and systems development, these guidelines explain in an easy-to-understand way how you can improve your requirements engineering processes. The guidelines are applicable for any type of application and, in general, apply to both systems and software engineering. The guidelines here range from simple 'common sense' to those which propose the introduction of complex new methods. The guidelines and process improvement schemes have been organised so that you can pick and choose according to your problems, goals and available budget. There are few dependencies between guidelines so you can introduce them in any order in your organisation. Guidelines presented in the book * are consistent with ISO 9000 and CMM * are ranked with cost/benefit analysis * give implementation advice * can be combined and applied to suit your organisation's needs * are supported by a web page pointing to RE tools and resources