The Multi-echelon Inventory Model And Optimization Algorithm Of Large Equipment’s Maintenance Spares-parts

The maintenance spare parts which is needed for complex structure of large equipment are with great variety, high added value, long manufacturing cycle and high safety stock, they require a huge amount of inventory guarantee the normal operation of equipment, the large equipment maintenance spare parts inventory system is usually composed of multi-echelon inventory, inventory optimization is able to reasonably configure storage capacity at all levels, reduce the problem of spare parts shortages caused by long purchase lead time, speed up the supply of spare parts, reduce inventory costs, improve equipment operating efficiency.Scientific classification of maintenance spare parts is the premise of the development of inventory policy, this paper studies the multi-level Inventory model based on the classification of large equipment maintenance spare parts. Companies spare parts classification situation departure, broken down for class C spare parts of more stock problematic, consider spare parts classification under influence of five factors:using AHP to evaluate the impact factors of weight, using fuzzy evaluation method and expert scoring method to carry out the evaluation of spare parts, using the method of feature selection and combining expert opinion to classify. For Cl maintenance spare parts, considering a number of different regional maintenance center and multiple service points, using the (s-l,s) replenishment policy, the objective function of the expected shortage of maintenance spare parts, the whole maintenance system inventory budget for the enterprise as a constraint, based on METRIC model, a three-echelon inventory model with the objective of minimizing the expected number of short supply was formulated. Studying optimization algorithm for solving inventory model. Using genetic algorithm toolbox to prepare multi-population genetic algorithm. At last, analysing case with parameters optimization, using it to obtain the optimum solution.The research results provide a scientific and reasonable method for the classification and optimization of maintenance spare parts of large equipment enterprises. The method can improve the inventory management level of maintenance spare parts, reduce the inventory cost, and improve the maintenance efficiency of the equipment.