Improving patient flow is a critical aspect of quality management in emergency departments and other healthcare settings. By improving the flow of patients in healthcare facilities, we can decrease wait times and boost patient and staff satisfaction. Many patients face physical pain and suffering while waiting for treatment in healthcare facilities. Long wait times may also result in treatable illnesses and injuries becoming chronic conditions. This dissertation includes three main chapters, corresponding to three essays on understanding and improving patient flow in outpatient clinics and emergency departments. In some outpatient clinics, lab tests must be completed before the clinic appointment, as doctors need to have the test results when seeing a patient. Achieving this tight coordination of a patient's testing and his or her subsequent doctor's appointment may be difficult in a facility where many physicians share the same testing resources. The second chapter presents a mixed-integer programming (MIP)-based approach to reduce the likelihood of a patient not completing testing in time for the clinic appointment. In the third chapter, we focus on improving patient flow in emergency departments by looking at the physician scheduling problem. We show that the scheduling of physicians has a direct impact on the waiting time of patients. Chapter 4 presents a new crowding measure in emergency departments that is based on patient volume and mix of patients. We assess the relevance and significance of the proposed measure
