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Research On The Method And Its Application Of Quality Measurement And Improvement For Process Fluctuation

Posted on:2004-07-06Degree:DoctorType:Dissertation
Country:ChinaCandidate:S Z WeiFull Text:PDF
GTID:1116360095452348Subject:Management Science and Engineering
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It is very important to improve product quality and competition for a enterprise applying advanced quality technology and quality control methods, which appeal researcher and practicer to design and produce low-cost, short-period, high quality&reliability product. These methods make enterprises win superiority competition. The tendency of current quality engineering is to reduce, restrain and control the fluctuation in the process.Quality loss function(QLF)is the basis of Taguchi.G method. It is more suitable to the practice using QLF to measure quality. This paper discusses the defect of quadratic loss function and studies the models of inverted Normal and inverted Gamma loss function. We explore the relationship between QLF and signal-to-noise(SN),put forward multivariate QLF model based on SN, which overcome the flaw that single-characteristic can not reflect multi- characteristic in practice. An example demonstrates the feasibility of this method. We also study the design of mean selection based on the minimum loss using Taguchi.G method, present the concepts of the ratio of quality loss and effective off-center. At last we explore the design of mean selection based on the maximum profit in the process of bin packing and improve the old model.Process Capability Index(PCI) is also an important method to measure and improve quality, which has play a key role in assuring quality evidence ,lowering cost and raising Customer Satisfaction Indexes(CSI) .This paper studies the applications of PCI and Control Chart from the actual viewpoint, and discusses the applications of the probability a, (3 ofType I , II error of the Control Chart, the detecting power and PCI based on X Control Chart. In addition we explore the relationship between QLF and PCI, put forward the concepts of relative loss and loss extent, adopt the Linear Plan to optimize PCI and decide the best loss extent of each process. An example is given. This method is also used to evaluate and select the suppliers in the global and dynamical angle. This paper comes up with a new algorithm of multivariate PCI based on Coefficient of Variation(CV) aiming at the flaw of the principle component analysis. At last an example proves its fitness.Using Taguchi.G method to create financial product is a new research direction Financial Engineering. Quality idea of Taguchi.G reflects people' pursuit and assumption of avoiding risk for investment decision, which aims at reducing fluctuation. At first wecompare some kinds of investment loss function, analyze their defects and take the eignvalue of covariance matrix as the measurement of investment risk, the principle component as the information of investment market, SN and CV of the principle component as balance relationship between the profit and risk. Then different portfolio selection indexes are given ,and new portfolio selection models are presented ,which are different from H.Markowitz model. At last an example is also given. The idea and research method in this paper exploit a new view for creating financial product.
Keywords/Search Tags:Quality Improvement, Taguchi.G Method, Quality Loss function, Process Capability Index, Signal to Noise Ratio, Portfolio Selection.
PDF Full Text Request
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