导　　师： 杨雷;吴宾

学科专业： 1201

授予学位： 硕士

作　　者： ;

机构地区： 华南理工大学

摘　　要： 本文主要目的是研究提高电梯层门板良品率的问题,以电梯层门板良品率为研究对象，运用先理论后实践的实证研究法从成本和质量两个角度出发，运用排列图从2011年中不良品中找出了“提高电梯层门板良品率”问题的主要因素为焊接变形，根据GR公司已通过ISO9000体系且实施了全面质量管理模式，以及质量水平处于三西格玛的现状，再通过六西格玛两种经典模式DMADV与DMAIC的比对，决定使用六西格玛经典模式DMAIC作为改善该问题的主要工具。结合六西格玛方法论中DMAIC的五大步骤，采取定性与定量的分析方法对焊接变形问题进行探讨与改善： 1、采用了SIPOC来界定了需要改善的流程，成立了六西格玛改善小组。 2、主要是对测量系统进行分析，保证了所采集的数据是可靠的。 3、用头脑风暴法及因果图找出潜在导致焊接变形的12个因子，再通过假设检验的方式进行统计性分析找出了影响该问题的6个关键因子。 4、通过小组成员的共同努力寻找出3个对案因子最佳的改善方案，并用实验设计找出余下3个控制因子的最佳条件。 5、根据上面找到的原因，针对6个关键因子进行改善： 1）从人手固定焊接改为增加气动夹具夹紧门边进行焊接。 2）由焊接时无预变形改为预留1.5mm的预变形量。 3）将封头及加强筋固定方式由双面胶粘贴改为压焊方式。 4）确定了焊接相关最佳参数为焊接时间1.5s、电流变化不超过10/%、焊丝直径为1.0mm。 6、通过标准化文件、作业指导书等文件对改善成果加以维护。 通过上述改善，提高了的电梯层门板良品率提高到99/%以上，达到了预期目标。 最后，为了验证改善投入的合理性，针对已改善的结果采取了质量成本原理和朱兰质量成本模型进行分析，充分证明了该项目的投入与产出的比例是合理的，没有产生质量冗余，并建立了以预防为主的质量管理思路，该点也是本论文有别于其他同类文章的独特之处。 The purpose of this thesis is to study how to improve the yield rate of elevator shutters.From the perspectives of cost and quality, this thesis uses empirical approach, which includestheoretical analysis followed by practice, to study the yield rate of shutters. By Pareto chart, thisthesis finds out that the main factors hindering the yield rate of2011is welding deformation. Inthe light of the fact that GR Company has passed ISO9000and has implemented overall qualitymanagement mode with product quality at Three Sigma level, the thesis makes a comparisonbetween DMADV and DMAIC, the two primary Six Sigma methodologies, and finallysuggests implementing DMAIC to solve the yield rate problem. Given the five improvementsteps of DMAIC, this thesis analyzes the problem of welding deformation and finds solutions inboth qualitative and quantitative manner. 1. Define the processes that need improvement by using SIPOC and set up Six Sigmaimprovement team. 2. Analyze the measurement system to ensure the reliability of collected data. 3. Find out12potential factors that may cause welding deformation by brain storm andcause-and-effect diagram, and later statistically analyze and define6key factors out of the12by using hypothesis testing. 4. Figure out the best solution to solve3factors by teamwork and then further to find outsolutions for the remaining3factors by experimental design. 5. Improvement solutions for the6factors 1/) Adopt air-operated clamping fixture when welding instead of fixing manually. 2/) Reserve1.5mm instead of no predeformation. 3/) Fix shell cover and stiffener by welding instead of using adhesive. 4/) Define optimum welding parameters:1.5s welding time, less than10/%current changes,1.0mm welding wire diameter. 6. Maintain improvement results by publishing standardization documents and operationinstructions. By the above-mentioned ways, the yield rate of shutters is raised and expected target ismet. Lastly, this thesis uses quality cost theory and quality cost model of Joseph M. Juran toanalyze and verify the rationality of the input, fully proving that the input-outcome ratio is reasonable without redundancy. Moreover, the thesis put forward “prevention first” qualitymanagement solution, which is a unique feature of this thesis when comparing with other thesesof this kind.

关 键 词： 六西格玛 电梯层门 质量改进

分 类 号： [F426.4 F273.2]

领　　域： [经济管理] [经济管理] [经济管理]