Consolidating maintenance spares

The inventory of spare parts that a firm holds depends on the number of wor king parts and age of the equipment to be serviced, the expected failure ra te associated with each working part, and the acceptable level of service. We model the problem of consolidation of spare parts to reduce overall inve ntory as an integer program with a nonlinear objective function. A linear r eformulation of this model is obtained that helps solve some practical inst ances. A more compact implicit formulation is developed and solved using a specialized branch-and-price technique. We also demonstrate how this specia lized branch-and-price technique is modified to devise a very effective heu ristic procedure with a prespecifiable guarantee of quality of solution pro duced. This provides a practical and efficient methodology for maintenance spare consolidation.