One of main ideas that motivate the implementation of health care information technology (HIT) is that these systems support clinical workflow and thereby decrease medical errors. However, many argue that the model of clinical processes upon which these systems are based shows a fragile compatibility with the contingent and pragmatic workflow of care providers. But, why is that so? And what are the attributes of clinical workflow that challenge this model? This book aims to gain insight into these attributes and their interplay with HIT systems in practice. To do so, we draw upon a process-oriented, user-centered evaluation of clinical workflow in the medication process involving a computerized physician order entry system. The research was conducted at Erasmus Medical Center, an academic hospital in Rotterdam, The Netherlands, between 2003 and 2009. This book can be helpful for system designers, implementers, and evaluators interested in making a fit between clinical workflow and HIT systems.