基于分段函数的威布尔型备件需求量近似算法

Approximate Method of Spares Demand Prediction for Weibull Distribution Items Based on Piecewise Function

威布尔型备件需求预测模型涉及多重无穷级数,计算较为困难。一般采用的近似计算方法,往往存在着较大误差。通过研究更新函数的有关性质,提出了一种利用分段函数近似更新函数的威布尔型备件需求函数近似方法,避免了备件需求预测计算复杂的问题。理论分析表明:提出的近似算法保证了获得的备件需求量要小于工程近似算法。最后通过算例,仿真验证了提出的近似算法的近似效果较好,紧贴仿真结果,精度优于近似计算方法,满足实际保障需要,有利于工程需求。

Demand prediction model for spare parts with Weibull distribution involves multiple infinite series, therefore, spares demand calculation is a difficult issue. The approximate calculation method generally used is often subject to large errors. According to the principle of renewal function, the approximated demand calculation method for spares of Weibull distribution using piecewise function to approximate the renewal function is proposed. It effectively avoids the issue of computational complexity for spares demand prediction. Theoretical analysis shows that the proposed approximated algorithm ensures the calculation result of spares demand is less than that of engineering approximation algorithm. According to the given example, the simulation verifies that the proposed approximation algorithm has a better approximation effect, meets the practical support demand as well as the engineering demand.