As the business environment has become more and more turbulent over the past decade, information technology has begun to run into the danger of becoming an impediment rather than a motor of progress. In order to deal with the need for rapid, continuous change, computer science is challenged to develop novel interrelated information and communication technologies, and to align them with the social needs of co-operating user groups, as well as the management requirements of formal organisations. Workflow systems are among the most advertised technologies addressing this trend, but they mean different things to different people. Computer scientists understand workflows as a way to extract control from application programs, thus making them more flexible. Bureaucratic organisations (and most commercial products) perceive them as supporting a linear or branching flow of documents from one workplace to another - the next try after the failure cf office automation. This book takes another perspective, that of the modem customer-driven and groupwork-oriented process organisation. Extending the language-action perspective from the CSCW field, its customer-oriented view of workflows enables novel kinds of business process analysis, and leads to interesting new combinations of information and co-operation technologies. Schal's empirical studies show some of the pitfalls resulting from a naive use of these technologies, and exemplify ways to get around these pitfalls.