Operational research and cost containment: a general mathematical model of a workstation

To facilitate planning and management, I have derived a mathematical model describing the dynamics of a workstation that receives a mixture of routine and emergency specimens. The model parameters include the maximal specimen-processing rate (to be defined by personnel representatives) and the longest delay allowed for emergency specimens at the workstation. Based on the model, a computer-simulation technique has been developed to maximize the length of time (planned pauses) during which the workstation could be closed without causing undue delay of routine and emergency specimen results. The application of this technique is illustrated with real data, in which more than 50% of the specimens were emergency specimens. Three pauses, constituting 35% of working hours, could be introduced with a negligible impact on the turnaround time of emergency specimens (mean increase = 8 min). The model may also be used to derive, as a function of time of day, the largest extra workload that may be presented to a workstation without creating overwork. The workload could be increased by 45%, provided that all additional specimens arrived before noon.