Calculation of Spare Parts in a Car Service Enterprise Based on Evaluating the Average Time of Details Serviced Automobiles

Karimov Nijat Ashraf

doi:10.11648/j.ijsts.20170505.12

Abstract

The purpose of the work is the development of a technique for calculating spare parts in an auto service company based on an analysis of statistical information on the failure of details of each standard accumulated on daily information on the replacement of spare parts for serviced vehicles in previous planning periods. In the theory of system reliability, the calculation of the failure distribution function usually uses information on the main characteristic of failures - the time between failures, and in the absence of such information, it is necessary to use information on the number of failures at the time of receipt for maintenance of cars in this auto service plant. In this connection, the relationship between the distribution functions of these random variables is established using the reciprocity of the distribution processes to failure and the number of failures. For each of the competing theoretical functions of the distribution of the operating time to failure, an estimate is made of the average operating time of the details of each standard in the auto service plant on the basis of actual demand. The estimates obtained make it possible to calculate the number of spare parts for the subsequent replenishment period of the SPIE.

Highlights

An analysis of previous work on the calculation of spare parts in car service stations (CSS) [1] shows that in recent years, most Russian auto service enterprises have been using the system for determining the need for spare parts, which is based on actual demand and individual details for the previous period Work
The relationship established between the distribution functions of the operating time to failure and the number of failures is substantially used in this paper, the use of which makes it possible to reduce the problem of estimating the mean time to failure to solve a nonlinear algebraic equation
A value of CAcAdab is adopted satisfying the relation CAcAdab ≤ CH J_and according to the value of the series (11), the sufficiency index of a set of SPIE-O is determined by the ratio gh ≥ CAcAdab⁄CH J_If CH J_is less than 0.9, the value gh = CAcAdab is accepted from reasoning on importance of feasible functions and the importance of the economic expediency

Summary

Introduction

An analysis of previous work on the calculation of spare parts in car service stations (CSS) [1] shows that in recent years, most Russian auto service enterprises have been using the system for determining the need for spare parts, which is based on actual demand and individual details for the previous period Work.The most important a priori information, which determines the amount of spare parts, is the theoretical model of failures that is taken into account in calculating the number of failures [2,3,4,5,6].First of all, on the basis of failure statistics, the best model for the distribution of failures among a finite number of competing theoretical distribution functions is chosen, based on the Kolmogorov-Smirnov agreement, for the first part of each component model, including the diffusion (monotonic and no monotonic) distributions. For the best model for the distribution of failures of parts of each standard, an estimate of the mean time to failure (i.e., the average time between successive replacements) of the details of each standard is calculated taking into account the adequacy index of ensuring non-renewable spare parts [9]. According to these estimates, the expected size of the spare parts of each standard is determined, taken as the initial approximation of the proposed algorithm for calculating spare parts for the subsequent replenishment period SPIE. The choice of the best model for the distribution of failures of the part and detail of each

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