فهرس المقالات Process capability indices

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  1 - Capability Indices for Rayleigh Process
  Davoud Dariae Bahram Sadeghpour Gildeh
  Monitoring, control and improvement of quality are important for companies. Process capability indices (PCIs) are tools widely used by the industries to determine the quality of their products and the performance of their manufacturing processes. Classic versions of the أکثر

  Monitoring, control and improvement of quality are important for companies. Process capability indices (PCIs) are tools widely used by the industries to determine the quality of their products and the performance of their manufacturing processes. Classic versions of these indices were constructed for processes whose quality characteristics have a normal distribution. But, many of these characteristics do not follow this distribution. In such a case, the classic PCIs must be modified to take into account the non-normality, because the effect of this non-normality can lead to misinterpretation of the process capability and ill-advised business decisions. A non-normal model is the Rayleigh distribution which is very useful. This paper proposes a Clements’s method to estimate the PCIs for Rayleigh processes. Finally, an example to evaluate its performance is presented. تفاصيل المقالة
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  2 - Estimating process capability indices using ridge regression
  S Raissi R Noorossana
  Process capability indices show the ability of a process to produce products according to the pre-specified requirements. Since final quality characteristics of a product are usually interrelated to its previous amounts in earlier workstations, one need to model and con أکثر

  Process capability indices show the ability of a process to produce products according to the pre-specified requirements. Since final quality characteristics of a product are usually interrelated to its previous amounts in earlier workstations, one need to model and consider the relationship among them to assess the process ca-pability properly. Hence, conducting process capability analysis in multivariate environment is inevitable; unfortunately, the analysis in multivariate environment is usually complex and requires extensive calcula-tions. Sometimes it is preferable to simplify the analysis by assuming independency among quality character-istics and evaluating process performance with respect to each individual quality characteristic using univari-ate process capability indices such as CP, CPK, CPM, and CPMK. However, this simplification introduces some error in the analysis leading to under or overestimation of the process capability index. This paper models the interrelationship among quality characteristics that are produced in different workstations to provide an over-all process capability index. Ridge residual regression is used as a vehicle to evaluate process capability and helps quality engineers to provide a reasonable quality policy for controlling and reducing variation in quality characteristics. تفاصيل المقالة
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  3 - Multivariate process capability indices on the presence of priority for quality characteristics
  S Raissi
  Multivariate Process Capability Indices (MPCI) show how well a manufacturing process can meet specifica-tion limits when quality characteristics enclose a relative correlation. Process capability is an important and commonly used metric for assessing and improving the q أکثر

  Multivariate Process Capability Indices (MPCI) show how well a manufacturing process can meet specifica-tion limits when quality characteristics enclose a relative correlation. Process capability is an important and commonly used metric for assessing and improving the quality of a production process. When quality charac-teristics of a product are correlated then an attractive comes close to MPCI methods, which are not usually an easy task to carry out. In this investigation after a full reviewing of the MPCI, a simple method to estimate product capability indices based on ridge regression models in the presence of priority for quality characteris-tics is presented. The technique is demonstrated for evaluation of product capability through the use of an ex-ample which shows performance of the proposed method. تفاصيل المقالة