BEDS - Bed Evaluation & Design System

BEDS evaluates patient flow in hospitals. Specifically, BEDS evaluates the occupancy of beds and the probability of receiving a bed on arrival to the hospital.
BEDS is built on the assumption that patients arrive with a stationary intensity, and that the distribution governing their length-of-stay is also stationary. Thus, BEDS works only when modeling inpatient wards.
BEDS further assumes a setup consisting of a number of patient types and wards. The wards contain a fixed capacity. Patient types are defined by their arrival intensity (how many arrive per day on average), and their average length-of-stay. Patients have a single preference for hospitalization in a specific ward. If the preferred ward is fully occupied on arrival, the patient is relocated to an alternative ward with a known probability.
Several scientific studies have shown that this simple setup is an adequate approximation for describing the occupancy in inpatient wards.