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Chi-hyuck Jun - One of the best experts on this subject based on the ideXlab platform.

  • a variable sampling plan using generalized multiple dependent state based on a one sided Process Capability Index
    Communications in Statistics - Simulation and Computation, 2019
    Co-Authors: Srinivasa G Rao, Muhammad Aslam, Chi-hyuck Jun
    Abstract:

    In this manuscript, a sampling plan based on one-sided Process Capability Index is designed using the generalized multiple dependent state (GMDS) sampling. The operating characteristic function is ...

  • Bootstrap confidence intervals of generalized Process Capability Index Cpyk for Lindley and power Lindley distributions
    Communications in Statistics - Simulation and Computation, 2017
    Co-Authors: Sanku Dey, Mahendra Saha, Sudhansu S. Maiti, Chi-hyuck Jun
    Abstract:

    AbstractOne of the indicators for evaluating the Capability of a Process is the Process Capability Index. In this article bootstrap confidence intervals of generalized Process Capability Index (GPCI) proposed by Maiti et al. (2010) are studied through simulation when the underlying distributions are Lindley and Power Lindley distributions. Maximum likelihood method is used to estimate the parameters of the models. Three bootstrap confidence intervals namely, standard bootstrap (SB), percentile bootstrap (PB) and bias corrected percentile bootstrap (BCPB) are considered for obtaining confidence intervals of GPCI. A Monte Carlo simulation has been used to investigate the estimated coverage probabilities and average width of the bootstrap confidence intervals. Simulation results show that the estimated coverage probabilities of the percentile bootstrap confidence interval and the bias-corrected percentile bootstrap confidence interval get closer to the nominal confidence level than those of the standard boot...

  • A mixed control chart using Process Capability Index
    Sequential Analysis, 2017
    Co-Authors: Muhammad Aslam, Chi-hyuck Jun, Nasrullah Khan, Liaquat Ahmad, Jaffer Hussain
    Abstract:

    ABSTRACTControl charts are considered as a compulsory tool for the monitoring and improvement of the quality of products. The commonly used attribute and the variable control charts are unsatisfactory for Process monitoring. To overcome this difficulty, we proposed a monitoring scheme that is an improved technique based on the joint merits of the attribute as well as the variable control charts. The control chart coefficients have been determined for in-control and out-of-control situations for specified average run length values using simulation. The efficiency of the proposed control chart has been evaluated using average run length criteria for different values of the Process settings. A practical example has been studied for implementation of the proposed technique. It has been observed that the proposed chart performs well for the mixed technique under the Process Capability Index.

  • a proposed procedure for variable sampling plans design based on Process Capability Index
    The Journal of Engineering Research, 2017
    Co-Authors: Muhammad Aslam, Muhammad Azam, Chi-hyuck Jun
    Abstract:

    The article presents the tightened-normal-tightened acceptance sampling plan using the Process Capability Index C pk . The plan parameters of the proposed plan are obtained by solving an optimization problem such that the producer’s risk and the consumer’s risk are satisfied simultaneously for several specified combinations of acceptable quality level and limiting quality level. The plan parameters are tabulated and discussed for the industrial use when the fractions non-conforming beyond the lower and the upper specification limits are symmetric or asymmetric. We illustrate the proposed plan with the help of a real example. We compare the efficiency of the proposed plan with the existing sampling plans.

  • the design of a new repetitive sampling control chart based on Process Capability Index
    Transactions of the Institute of Measurement and Control, 2016
    Co-Authors: Liaquat Ahmad, Muhammad Aslam, Chi-hyuck Jun
    Abstract:

    Control charts are widely used to monitor manufacturing Processes for a deterioration in stability. We propose repetitive group sampling control charts based on the Process Capability Index Cpk for monitoring Process average when the quality characteristic follows a normal distribution. The performance of the repetitive Cpk control chart is reported and compared with the existing control chart in terms of the average run length. It is found that the proposed control chart is effective for quickly detecting small shifts in the Process mean.

Muhammad Aslam - One of the best experts on this subject based on the ideXlab platform.

  • inspection plan based on the Process Capability Index using the neutrosophic statistical method
    Mathematics, 2019
    Co-Authors: Muhammad Aslam, Mohammed Albassam
    Abstract:

    The Process Capability Index (PCI) has been widely used in industry to advance the quality of a product. Neutrosophic statistics is the more generalized form of classical statistics and is applied when the data from the production Process or a product lot is incomplete, incredible, and indeterminate. In this paper, we will originally propose a variable sampling plan for the PCI using neutrosophic statistics. The neutrosophic operating function will be given. The neutrosophic plan parameters will be determined using the neutrosophic optimization solution. A comparison between plans based on neutrosophic statistics and classical statistics is given. The application of the proposed neutrosophic sampling plan will be given using company data.

  • a variable sampling plan using generalized multiple dependent state based on a one sided Process Capability Index
    Communications in Statistics - Simulation and Computation, 2019
    Co-Authors: Srinivasa G Rao, Muhammad Aslam, Chi-hyuck Jun
    Abstract:

    In this manuscript, a sampling plan based on one-sided Process Capability Index is designed using the generalized multiple dependent state (GMDS) sampling. The operating characteristic function is ...

  • Statistical Monitoring of Process Capability Index Having One Sided Specification Under Repetitive Sampling Using an Exact Distribution
    IEEE Access, 2018
    Co-Authors: Muhammad Aslam
    Abstract:

    This paper proposes a control chart using repetitive sampling for monitoring Process Capability Index having one-sided specification limit using an exact distribution. The performance of the proposed chart is evaluated in terms of average run lengths using the exact probability distribution of the Process Capability Index. The result shows that the proposed chart is more efficient by indicating the quicker out-of-control signals than the one using single sampling.

  • A mixed control chart using Process Capability Index
    Sequential Analysis, 2017
    Co-Authors: Muhammad Aslam, Chi-hyuck Jun, Nasrullah Khan, Liaquat Ahmad, Jaffer Hussain
    Abstract:

    ABSTRACTControl charts are considered as a compulsory tool for the monitoring and improvement of the quality of products. The commonly used attribute and the variable control charts are unsatisfactory for Process monitoring. To overcome this difficulty, we proposed a monitoring scheme that is an improved technique based on the joint merits of the attribute as well as the variable control charts. The control chart coefficients have been determined for in-control and out-of-control situations for specified average run length values using simulation. The efficiency of the proposed control chart has been evaluated using average run length criteria for different values of the Process settings. A practical example has been studied for implementation of the proposed technique. It has been observed that the proposed chart performs well for the mixed technique under the Process Capability Index.

  • a proposed procedure for variable sampling plans design based on Process Capability Index
    The Journal of Engineering Research, 2017
    Co-Authors: Muhammad Aslam, Muhammad Azam, Chi-hyuck Jun
    Abstract:

    The article presents the tightened-normal-tightened acceptance sampling plan using the Process Capability Index C pk . The plan parameters of the proposed plan are obtained by solving an optimization problem such that the producer’s risk and the consumer’s risk are satisfied simultaneously for several specified combinations of acceptable quality level and limiting quality level. The plan parameters are tabulated and discussed for the industrial use when the fractions non-conforming beyond the lower and the upper specification limits are symmetric or asymmetric. We illustrate the proposed plan with the help of a real example. We compare the efficiency of the proposed plan with the existing sampling plans.

Muhammad Azam - One of the best experts on this subject based on the ideXlab platform.

  • a proposed procedure for variable sampling plans design based on Process Capability Index
    The Journal of Engineering Research, 2017
    Co-Authors: Muhammad Aslam, Muhammad Azam, Chi-hyuck Jun
    Abstract:

    The article presents the tightened-normal-tightened acceptance sampling plan using the Process Capability Index C pk . The plan parameters of the proposed plan are obtained by solving an optimization problem such that the producer’s risk and the consumer’s risk are satisfied simultaneously for several specified combinations of acceptable quality level and limiting quality level. The plan parameters are tabulated and discussed for the industrial use when the fractions non-conforming beyond the lower and the upper specification limits are symmetric or asymmetric. We illustrate the proposed plan with the help of a real example. We compare the efficiency of the proposed plan with the existing sampling plans.

  • various repetitive sampling plans using Process Capability Index of multiple qualitycharacteristics
    Applied Stochastic Models in Business and Industry, 2015
    Co-Authors: Muhammad Aslam, Muhammad Azam, Chi-hyuck Jun
    Abstract:

    In this manuscript, three repetitive types of sampling plans using the generalized Process Capability Index of multiple characteristics are presented, which include a repetitive sampling plan, a resubmitted sampling plan and a multiple dependent state repetitive sampling plan. The plan parameters of these sampling schemes are determined through the nonlinear optimization solution. The comparison among these proposed plans is made in terms of the average sample number required. The use of the proposed plans is given with the help of an industrial example. Copyright © 2015 John Wiley & Sons, Ltd.

  • a new mixed variable lot size sampling plan based on Process Capability Index
    Journal of Testing and Evaluation, 2015
    Co-Authors: Muhammad Aslam, Saminathan Balamurali, Muhammad Azam, Chi-hyuck Jun
    Abstract:

    A new mixed sampling plan with a variable lot size plan is developed in this manuscript using the Process Capability Index. The operating characteristic function of the proposed plan is derived and the plan parameters are determined using the non-linear optimization procedure for symmetric and asymmetric fraction non-conforming cases. It is also shown that the proposed plan is more efficient than existing acceptance sampling plans. Industrial data is presented to explain the application of the proposed plan.

  • mixed multiple dependent state sampling plans based on Process Capability Index
    Journal of Testing and Evaluation, 2015
    Co-Authors: Muhammad Aslam, Saminathan Balamurali, Muhammad Azam, Srinivasa G Rao, Chi-hyuck Jun
    Abstract:

    In this paper, a mixed multiple dependent state sampling plan based on the Process Capability Index is presented for a quality characteristic of interest follows a normal distribution. The parameters of the proposed plan are determined with regard to the producer’s and consumer’s risks for specified values of acceptable quality level and limiting quality level. Tables containing parameters of the proposed plan are provided for symmetry and asymmetry cases. The advantages of the proposed plan over the attribute plan in terms of the sample size are discussed. An industrial example is given to explain the proposed procedure.

  • multiple dependent state sampling plan based on Process Capability Index
    Journal of Testing and Evaluation, 2013
    Co-Authors: Muhammad Aslam, Muhammad Azam, Chi-hyuck Jun
    Abstract:

    This paper extends the idea of multiple dependent state sampling plans to the case of using Process Capability Index when the quality characteristic of the product follows the normal distribution. The plan parameters are determined using the optimization Process with minimum values of sample size so that the specified producer’s risk and consumer’s risk should be satisfied simultaneously for given values of acceptable quality level and limiting quality level in terms of fraction defective beyond two specification limits. The plan parameters are determined under symmetric and asymmetric cases of fraction defective. The advantage of the proposed plan is discussed over the single variable sampling plan. A real example is presented to illustrate the proposed plan in practice.

Mohammad Abdolshah - One of the best experts on this subject based on the ideXlab platform.

  • Measuring Loss-Based Process Capability Index and Its Generation with Fuzzy Numbers
    Mathematical Problems in Engineering, 2015
    Co-Authors: Mohammad Abdolshah
    Abstract:

    Loss-based Process Capability indices are appropriate and realistic tools in order to measure the Process Capability. Among them, Index and its generation are well-known loss-based Process Capability indices, whose concepts are based on the worth (the opposite concept of loss). Sometimes, in order to calculate and there are some uncertainties in observations, so fuzzy logic can be employed to manage the uncertainties. This paper investigates fuzzification of Process Capability Index and its generation . In order to find the membership function of Process Capability indices and , the α-cuts of fuzzy observation were employed. Then with an example of fuzzy Process Capability Index, and were calculated and compared. Results showed that fuzzy was more sensitive compared with and was increased while the target departs (asymmetric tolerance). This example also showed that, with departure from the target, variation of fuzzy and consequently its fuzziness were increased.

  • Development Of A Fuzzy Loss-based Process Capability Index
    2013
    Co-Authors: Mohammad Abdolshah
    Abstract:

    Process Capability indices are appropriate tools in order to measure the inherent Capability of Process, but most of these indices cannot take into account the losses of a Process such as rejects, while in today’s competitive business environment, it is becoming more and more important for companies to evaluate and minimize their losses. Since most of Process Capability indices do not consider the losses, the Process Capability indices based on losses can help manufacturers to understand the real Capability of their Processes in order to improve them. Literature review showed two main gaps in loss-based Process Capability indices. The first gap is that there is not a loss-based Process Capability Index, which has more features such as reject based, asymmetric, bounded, and target based. In order to overcome this problem, an appropriate loss function (asymmetric inverted normal loss function) was employed to propose a new loss-based Process Capability Index. The methodology is to compare the standard loss for a capable Process with other cases. The proposed Process Capability Index is bounded, asymmetric and it is able to provide a more realistic metric to evaluate and predict the performance of Processes. The second gap in literature review is that among all loss-based Process Capability indices, just Cpm has been fuzzificated, while literature review showed that the Index Cpm is not an appropriate Process Capability Index. Then fuzzy logic and operation research model were employed to fuzzificate the new proposed loss-based Process Capability Index. The α-cuts of the fuzzy observation was the method employed to find the fuzzy membership function of the new loss-based Process Capability indices. The result of this study is a new loss-based Index with more specifications such as mean-based, target- based, variation-based, bounded, and loss-based compared with other Process Capability indices. The new Process Capability Index was fuzzificated using α-cut method. Therefore a fuzzy loss-based Process Capability Index was developed that is useful for vague data. In order to validate the new loss-based method, the sensitivity of this Index to Process specifications was studied. Sensitivity analysis showed that this Index is sensitive to the mean, variation, and target of data. The new Index has 99.6% relationship with the loss especially asymmetric inverted normal loss function. This relationship with loss is the highest relationship compared with other Process Capability indices. Moreover a regression analysis showed that the new Index has the most relationship with the value of loss compared with other Process Capability indices.

  • A fuzzy Taguchi loss-based Process Capability Index
    International Journal of Quality Engineering and Technology, 2013
    Co-Authors: Mohammad Abdolshah
    Abstract:

    Process Capability indices are appropriate tools to measure the inherent Capability of a Process, but most of them do not take into account the losses of a Process. By integrating the Taguchi loss function and a Process Capability Index (Cpk), a new Process Capability Index called fuzzy Taguchi loss-based Process Capability Index (FTPCI) was developed. Due to the definitions of a capable Process or value of standard loss, the fuzzy approach to the result of the Index Cpk and Taguchi losses have been proposed. In order to construct this new fuzzy Process Capability Index, Mamdani fuzzy system consisting of the Taguchi loss and the Index Cpk was employed. Finally, an example on the usage of this Process Capability Index illustrated the results.

  • Measuring Process Capability Index Cpmk with fuzzy data and compare it with other fuzzy Process Capability indices
    Expert Systems with Applications, 2011
    Co-Authors: Mohammad Abdolshah, Rosnah Mohd Yusuff, Tang Sai Hong, Yusof Ismail, Aghdas Naimi Sadigh
    Abstract:

    The Index Cpmk is a well-known loss-based Process Capability Index. It can reveal more information about the location of the Process mean compared with other classic Process Capability indices. This Index is also more sensitive than other Capability indices to any deviations from Process mean. When there are some uncertainties in observations, fuzzy logic can be employed to manage these uncertainties. There is some research on different fuzzy Process Capability indices and this paper is an extension of Tsai and Chen (2006), Chen, Lin, and Chen (2003) for the Process Capability Index Cpmk of fuzzy numbers. In order to find the membership function of Process Capability Index Cpmk, the α-cuts of the fuzzy observation were employed. An example of fuzzy Process Capability Cpmk calculator was illustrated and compared with other classic fuzzy Process Capability indices C ~ p , C ~ pl , C ~ pu , C ~ pk and C ~ pm . Results showed that fuzzy C ~ pmk has the advantages of both C ~ pk and C ~ pm . Since the Index Cpmk is a more sensitive Index compared with other classic indices, the fuzzy Process Capability Index C ~ pmk can be a more sensitive fuzzy Index compared with C ~ p , C ~ pl , C ~ pu , C ~ pk and C ~ pm .

  • New Process Capability Index using Taguchi loss functions
    Journal of Applied Sciences, 2009
    Co-Authors: Mohammad Abdolshah, Rosnah Mohd Yusuff, Sai Hong Tang, Yusof Ismail
    Abstract:

    Classic Process Capability indices such as Ca, Cp and Cpk are well-known Process Capability indices, which are using widely. Since, Process Capability indices predict the Capability of a Process, they must have a significant relation with rate of rejects and losses. Studies showed that mostly Process Capability indices do not have a significant relation with rate of rejects or losses. Therefore, the loss-based indices are more appropriate and suitable indices to predict the Capability of a Process. In order to define a new loss-based Process Capability Index, Taguchi loss functions were employed and this study proposed a novel Process Capability Index called Taguchi-based Process Capability Index (TPCI). The methodology of this Process Capability Index is based on standard rate of rejects for a capable Process compared to other cases. Therefore, this study develops a new Process Capability Index, which is Taguchi loss function-based and sensitive to losses. This new Process Capability Index can provide a realistic and applicable metric to evaluate a Process.

W. L. Pearn - One of the best experts on this subject based on the ideXlab platform.

  • estimating Process Capability Index cpk classical approach versus bayesian approach
    Journal of Statistical Computation and Simulation, 2015
    Co-Authors: W. L. Pearn
    Abstract:

    Process Capability Index Cpk has been the most popular one used in the manufacturing industry dealing with problems of measuring reproduction Capability of Processes to enhance product development with very low fraction of defectives. In the manufacturing industry, lower confidence bound (LCB) estimates the minimum Process Capability providing pivotal information for quality engineers to monitoring the Process and assessing Process performance for quality assurance. The main objective of this paper is to compare and contrast the LCBs on Cpk using two approaches, Classical method and Bayesian method.

  • New generalization of Process Capability Index Cpk
    Journal of Applied Statistics, 1998
    Co-Authors: W. L. Pearn
    Abstract:

    Summary The Process Capability Index Cpk has been widely used in manufacturing industry to provide numerical measures of Process potential and performance. As noted by many quality control researchers and practitioners, Cpk is yield-based and is independent of the target T. This fails to account for Process centering with symmetric tolerances, and presents an even greater problem with asymmetric tolerances. To overcome the problem, several generalizations of Cpk have been proposed to handle Processes with asymmetric tolerances. Unfortunately, these generalizations understate or overstate the Process Capability in many cases, so reflect the Process potential and performance inaccurately. In this paper, we first introduce a new Index Cp"k, which is shown to be superior to the existing generalizations of Cpk. We then investigate the statistical properties of the natural estimator of Cp"k, assuming that the Process is normally distributed.

  • A PRACTICAL IMPLEMENTATION OF THE Process Capability Index Cpk
    Quality Engineering, 1994
    Co-Authors: W. L. Pearn, Kuen-suan Chen
    Abstract:

    Abstract The generalization , a modification of the Process Capability Index Cpm, not only takes the proximity of the target value into consideration but also takes into account the asymmetry of the specification limits. In this paper, based on the theory of testing hypothesis we develop a step-by-step procedure using estimator of for the practitioners in making decisions when the Process is normally distributed. An efficient MAPLE computer program is developed to calculate the corresponding p-value. For non-normal sample data, an example is presented that an approach based on Johnson transformation is to transform the nonnormal data to normality. The proposed decision making rule can be used to test whether the Process is capable or not.