Clinical work, including ordering, is known to be interruptive, multitasking, collaborative and distributed yet current clinical computer systems emphasize linear, normative and solitary work. Although the evidence of a work-technology disconnect is well documented by researchers, there is less understanding of the origins of this disconnect. Currently engineers and designers build systems based on descriptive or normative approaches. However, the increasing complexity of clinical work environments make predicting work patterns and work flow more challenging, if not impossible. Therefore, this suggests that new approaches are needed to build flexible systems that can support unanticipated work. The growth of health information technology investment presents an even more urgent motivation for building systems that can achieve high user acceptance and that are responsive to these complex socio-technical environments. This research uses a mixed-method approach consisting of a qualitative field study of physician ordering that collected documents, observations and interviews of pediatric inpatient physicians working in teams. Inductive analysis identified emerging physician work themes. Deductive analysis was used to characterize the larger contexts in which ordering occurs by using Cognitive Work Analysis (CWA)--a holistic systems analysis framework that indentifies constraints on work at multiple levels from the work environment to the worker. These combined results lead to visualizations and design implications for future systems that can support flexibility, cooperation and adaptation to unanticipated work situations. This work seeks to examine physician work more broadly from a systems perspective through two primary goals. The first is to apply the multi-dimensional cognitive work analysis framework to systematically characterize the work of pediatric inpatient teams including the visualization and technology design implications of the results. The second is to explore how CWA can be generalized to a clinical domain and extended to other clinical work environments and workers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]