Semiotics, the science of signs, has for many years been recognised as an important discipline for understanding information and communications. More recently it has found wider application in other areas of computer science, as it offers an effective insight into organisations and the computer systems that support them. An organisation may be viewed as a system of information and communication in which human actors, with the assistance of information technology, are able to process, represent, store and consume information. Computer systems that fit into an organisation and that support and enhance its performance and competitiveness, can be better delivered if semiotic principles are understood and applied. In this book semiotic methods are introduced and illustrated through three major case studies, which demonstrate how information systems can be developed to meet business requirements and support business objectives. It is the first such treatment, and will appeal to academics, systems developers and analysts.