농기계의 적정 예비품 보유를 위한 마코브 재고관리모델 분석

A Markov Inventory Control Model for Optimum Spare Units of Combine Harvester in Rice

The problem that we address is to determine the inventory stockage in a system which consists of n different subsystems in series(1-out-of-n: F). When a unit fails, it is required the replacement of spare units to keep the system availability high. The model is developed for an i-subsystem group has m operating i-units and has Ui spare units. The i.i.d. systems have a pool of spare units. With the Markov transitional probability of the i-subsystem, the steady-state system availability is calculated. The model formulates the problem of optimally allocating the spare units during each operating-cycle period, which maximizes the system availability constrained by the total inventory cost. The model is defined as the nonlinear integer prograrmming(NLIP) problem. The solution of this NLIP can be solved by the generalized reduced-gradient and branch-and-bound algorithms.