Study On Remanufacturability Evaluation And Remanufacturing Process Decision Methods Of Machine Tool

China is a machine tool manufacturing power in the world, and has the world’slargest consumption and holdings of machine tools. However, most machine tools arebackward in technique and running out of the service life period. It is estimated thatabout one million would be confronted with retirement and scrapping due to technologyor function during the12th Five-Year-Plan period. Machine tool remanufacturing, as anew manufacturing model of machine tool, has a significant effect of energy saving,material saving and environmental emissions reduction, in line with China’s strategicneeds of recycling economy, and low-carbon economy. Remanufacturability evaluationand remanufacturing process decision are key technologies of machine toolremanufacturing, urgently requiring the support of related theoretical basis.With the financial aid of the National Key Technology R&D Program for the12thfive-year plan (NO.2006BAF02A20) and the National Natural Science Foundation(51205295), study on remanufacturability evaluation and remanufacturing processdecision methods of machine tool are carried out, which can provide technical supportfor implementing machine tool remanufacturing. The main research contents are asfollows.Firstly, remanufacturing cost, the main influence factor for machine toolremanufacturability, are determined through an analysis from technical, economy andenvironmental benefit based on the development and current situation of machine tool inChina. Then, to solve the problem of remanufacturing cost diversity, an analysis model ofremanufacturing cost is presented based on activity-based costing method. Applying thismethod, remanufacturing costs of machine tool with different failure features can beobtained. The failure feature of machine tool and the corresponding remanufacturing costare saved as case storehouse. By comparing a used machine tool’s failure features withcase storehouse based on case-based reasoning method, its remanufacturing cost can bepredicted definitely. Finally, the market price of remanufacturing machine tool iscalculated through remanufacturing cost, tax and fee, warranty cost and target rate ofprofit. Remanufacturability evaluation model is established by comparing theremanufacturing machine tool’s market price with the new machine tool beforeremanufacturing and the machine tool whose performance is equivalent toremanufacturing machine. Secondly, resource strategy decision model of used parts is established from theviewpoint of remaining useful life estimation. Based on the failure data and performancedegradation data of used parts, weibull distribution and artificial neural network areintegrated to assess the remaining useful life. For the used parts with remaining usefullife, reliability is analyzed at the end of its first life and residual life in a quantitative wayrespectively, combined with the parts’ reliability threshold, the resource strategies of usedparts are determined, namely reuse, remanufacturing or recycle.Thirdly, an integrated model based on quality function deployment (QFD), fuzzylinear regression and zero-one goal programming (ZOGP) is proposed, in whichmachining time (T), machining quality (Q), machining cost(C), resource consumption(R), and environmental emission (E) are taken as decision objectives, while theengineering technology characteristics of each process stage as decision variables.Essentially, QFD provides the means for incorporating not only the correlation betweendecision objectives and decision variables but also the autocorrelation between decisionvariables. Fuzzy linear regression is employed for parameter estimation of the correlationand autocorrelation which are defined in a vague and imprecise manner. Finally, ZOGP isapplied as a decision tool to determine the optimal remanufacturing process.Fourthly, a support system for remanufacturability evaluation and remanufacturingprocess decision is developed. The architecture, function module design and operationalflow are given a detailed introduction.Finally, machine tool C6132A1is taken as an example to analyze the practices ofmachine tool remanufacturing in Guangzhou machine tool works from three aspects,namely remanufacturing process, remanufacturing scheme and comparison analysisbefore-and-after remanufacturing.