Simulation Research And Application Of Spare Parts Resource Allocation Based On Reliability Prediction

There is an increasing complexity of CNC machine tools in both function and structure.That has brought more challenges for resource allocation of CNC machine tools' spare parts.Hence,how to realize the rational allocation and optimization of spare parts in order to ensure the normal operation of CNC machine tools and complete production task has become a main constraint,for manufacturing enterprises,on improving productivity and reducing production cost.The research shows that there is a certain correlation between the faults of CNC machine tools.These relations include one-way relation and bidirectional relation.In addition,how to describe this relation quantificationally is very difficult and has become a hot spot at present.Considering the correlation of faults,the reliability of components can be predicted more accurately.As known to all,the accurate reliability prediction is an effective guarantee for the prediction of spare parts demand.The main research work of the thesis is as follows:(1)Because of the correlation of the structure and function of the CNC machine tools,the faults of each subsystem or parts are not independent.There is a correlation,difficult to quantitate,among them.Therefore,the thesis analyzed the common fault types of CNC machine tools in both functions and structure.Then the fault correlation is quantitatively described by using FMECA and DEMATEL.And the failure rate and reliability function considering the influence degree were established(2)A spare parts supply chain network model was built by simulation software Arena.Using the new reliability function,the paper predicted the reliability of equipment at a given threshold,which was converted to the input information of simulation model.Total operation cost,satisfaction and cycle were selected as the performance evaluation index of spare parts supply chain.(3)The FFZD4005 ball screw of N company was selected as the research object.Based on the analysis of fault correlation and fault records,the reliability function and failure rate of screw,nut,ball and reverser were constructed,which were verified.On the basis of obtaining the information of supply chain and product information,the performance level of the supply chain was considered before and after considering the fault correlation.The validity of the method was verified at last..Through this study,the correlation of each component of CNC machine tool was analyzed quantitatively.A method for constructing the failure rate and reliability function considering the influence degree was proposed.On the basis,the thesis put forward a method of spare parts allocation based on reliability prediction.Firstly,the simulation model of spare parts supply chain was constructed by using Arena simulation software.Secondly,the spare parts demand information was obtained based on the prediction of equipment's reliability by the new method.Then the performance level of spare parts supply chain was studied.Finally,the reliability function considering fault correlation was verified by the actual data of the enterprise.At the same time,the changes of the performance level of the spare parts supply chain before and after considering the fault correlation were discussed.Hence,the thesis provided a new method for the rational allocation and optimization of spare parts.