Stocking policies for blood components: a case of substitutable, perishable items

Abstract

Transfusion of blood from a healthy donor to a needy patient is a powerful therapeutic tool in modern medical practice. All major hospitals in India have blood banks, whose purpose is to provide 'safe' blood to patients whenever they require it. Blood is composed of several constituents which can be routinely extracted. Each of these serves a different function in the human body. A patient seldom requires all the constituents of human blood. Providing a patient with the specific component that he needs is preferable to giving him whole blood as this reduces health hazards. Further, such an action increases the availability of blood as the remaining components can be used for other patients. Hence blood component therapy makes effective and efficient use of a scarce resource. The problem of setting inventory levels for blood has been studied at various levels of complexity. Though blood component therapy has made the whole blood transfusion obsolete, almost all management science contributions deal with whole blood transfusions. The current study extends the inventory problem as a substitutable and perishable multiproduct model. The problem was considered under both multi-period and single period frameworks. The single period formulation has been solved through linear programming method in the deterministic case. The stochastic case has been modeled but not solved. The multi-period case is too complex to be analytically tractable. Hence a simulation model was constructed for the inventory process and a search method based on response surface methodology was developed which can be used by blood banks having no computational facility. The policies have been found to be performing well in terms of: 1. Efficient utilization of whole blood supply 2. Shortage rates and 3. Wastage rates The policies were also found to be robust. The methods developed in this study could be of use in any situation having the following characteristics: 1. Production of several items from several raw materials 2. Substitutability of these products 3. Perishability of the products.