Bed allocation to reduce overflow

Publication Type

Working Paper

Publication Date



Hospital emergency department boarding time, i.e. the duration between the patient bed request time and the patient admission time to inpatient wards, is a key performance in many hospitals. In order to avoid this waiting time to exceed certain level, some hospitals including the one under study in this paper may set a maximum boarding time (e.g. 6 hours) beyond which patients will be assigned to any available beds in the inpatient wards despite the medical specialties required. As a result, patients may be overflowed all over the hospital, causing physicians wasting their time on the way to visit their patients. High overflow rates also cause many other problems such as worse patient outcomes and more complicated bed allocation process. To address the overflow issue, we build an analytical model and propose two easy-to-compute bed allocation polices. We use the real data from the only university hospital in Singapore and a simulation model to evaluate the effectiveness of our proposed polices against the base case provided by the empirical study of the hospital. Through the simulation study, we show that the proposed policies can reduce the overflow rate from 18.91% to about 4.5% without sacrificing other performance measures. More surprisingly, our simulation studies suggest that the existing capacity actually can accommodate 50% more elective patients while keeping the overflow rate at a level of less than 10%.


bed allocation, patient overflow, M/M/c, optimization, discrete event simulation



Research Areas

Operations Management

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