Blood bank inventory policies: a computer simulation.

A computer model of a complete blood bank inventory system was constructed in order to determine the effects of three inventory policies on blood wastage and on work load while using inventory level to control shortages. The three policies were double crossmatching, use of older blood for patients more likely to use blood reserved for them, and use of older Rh-negative blood for compatible Rh-positive patients under limited conditions. Results of the simulation indicate that all three policies would be useful for reducing blood wastage within the constraints of increased work load, limited community supply of rarer blood types, and need of some patients for freshly drawn blood.