Showing papers in "Quality Technology and Quantitative Management in 2020"
TL;DR: In this article, the double exponentially weighted moving average (DEWA) is proposed to enhance the sensitivity of control charts for detecting small process shift in control charts. But, it may be done in different ways.
Abstract: Enhancing the sensitivity of control charts for detecting small process shift is desirable and may be done in different ways. In this paper, we propose the double exponentially weighted moving aver...
41 citations
TL;DR: RSS and its variation, extreme RSS, median RSS and neoteric RSS are employed to construct new memory type homogeneously weighted moving average (HWMA) control charts to monitor the process location to establish the better shift detection ability of the proposed charts.
Abstract: The process monitoring and construction of control charts involves the measurement of the quality characteristic under certain time and cost constraints. Ranked set sampling (RSS) is a very useful ...
30 citations
TL;DR: The Max-MCUSUM (Maximum multivariate cumulative sum) is one of the single control charts that plot single statistic as a representation of mean vector and covariance matrix as mentioned in this paper.
Abstract: Maximum multivariate cumulative sum (Max-MCUSUM) is one of the single control charts that plot single statistic as a representation of mean vector and covariance matrix. The Max-MCUSUM statistic ha...
24 citations
TL;DR: The newly proposed modified-mxEWMA chart uses the information of an auxiliary variable to improve the shift detection ability and performs very well for the monitoring of small to moderate shifts in the process location relative to the existing control charts.
Abstract: In this paper, we have proposed a new modified Exponentially Weighted Moving Average location control chart named as a modified-mxEWMA chart. The newly proposed chart uses the information of an aux...
23 citations
TL;DR: The accelerated failure time models have been integrated with robust regression techniques to find the accurate relationship among variables and a novel cumulative sum and two exponentially weighted moving average control charts have been constructed for optimal monitoring of Weibull-distributed quality variable with dependent influential covariate.
Abstract: Many monitoring approaches have been proposed to control reliability-related quality characteristics in single-stage processes. However, in practice, processes are made up of several sub-processes,...
19 citations
TL;DR: In this article, the authors considered an M/M/1/1 queueing system with differentiated server vacations and showed that the service is exponentially distributed, and both vacat...
Abstract: Impatience behavior of an M/M/1 queueing system, which has differentiated server vacations, is considered. Arrivals follow a Poisson process, service is exponentially distributed, as are both vacat...
19 citations
TL;DR: In this article, the reliability evaluation plays a critical role in upgrading the availability and productivity of automotive manufacturing industries by adopting the well-planned maintenance, but due to the lack of opera...
Abstract: Reliability evaluation plays a critical role in upgrading the availability and productivity of automotive manufacturing industries by adopting the well-planned maintenance. Due to the lack of opera...
17 citations
TL;DR: The proposed decision-making framework can help firms evaluate ERP systems effectively by collecting experts’ opinions in an uncertain environment and is applied to a firm in the high-tech industry in selecting the most appropriate ERP system.
Abstract: In recent years, the adoption of enterprise resource planning (ERP) is becoming essential for achieving fast and transparent information exchange, avoiding unnecessary waste and maintaining coordin...
15 citations
TL;DR: An optimal accelerated degradation test plan is presented considering the stochastic gamma process with constant stress loading, and an optimization model is formulated considering multiple stress factors and their interaction effects for offering a more realistic test plan.
Abstract: The effectiveness of accelerated degradation test and subsequent reliability assessment depends on the efficient test plan. Designing an accelerated test plan requires determining the optimal value...
14 citations
TL;DR: In this article, it is known that the error in estimating parameter(s) adversely affects the performance of control charts and that the charts with estimated control limits are usually assessed by some of the characte...
Abstract: It is now well known that the error in estimating parameter(s) adversely affects the performance of control charts. The charts with estimated control limits are usually assessed by some of characte...
13 citations
TL;DR: The maximum exponentially weighted moving average (MaxEWMA) chart is widely recognized as an efficient statistical process monitoring tool because of its ability to respond quickly against small-to-large errors as discussed by the authors.
Abstract: The maximum exponentially weighted moving average (MaxEWMA) chart is widely recognized as an efficient statistical process monitoring tool because of its ability to respond quickly against small-to...
TL;DR: In this paper, a hybrid exponentially weighted moving average (HEWMA) control chart for monitoring the process mean based on the normality assumption is proposed and the performance of control chart is seriously af...
Abstract: In practice, a hybrid exponentially weighted moving average (HEWMA) control chart for monitoring the process mean based on the normality assumption. The performance of control chart is seriously af...
TL;DR: The equilibrium balking strategies in the single-server Markovian queues with partial breakdowns and interruptible/setup closedown policy are studied, assuming that the customers decide whether to join or balk immediately after their arrival based on the reward-cost structure of the system.
Abstract: This paper studies the equilibrium balking strategies in the single-server Markovian queues with partial breakdowns and interruptible/setup closedown policy. That means the server may fail at any p...
TL;DR: In this article, a three-stage failure process divides a product's life into three stages: normal, minor defective and severe defective stages under the condition-based renewable warranty policy.
Abstract: A three-stage failure process divides a product’s life into three stages: normal, minor defective and severe defective stages. Under the condition-based renewable warranty policy, inspections are c...
TL;DR: An EWMA and region growing based control charting method is proposed for monitoring images of industrial products of which quality is either characterized by uniformity or a specific pattern, and is effective in quick detection of the fault but also accurate in estimating the fault size and location.
Abstract: The widespread application of machine vision system promotes the development of image-based statistical process control methodologies to improve the utilization of image data. Previous research has...
TL;DR: This article compares the performance of several widely used Poisson control charts in terms of the average run-length and makes recommendations in order to choose the best-performing control chart under different situations.
Abstract: In many real applications, the quality characteristics of interest may be in the form of attribute counts which are often modeled by a Poisson distribution. For the monitoring of such data, many di...
TL;DR: A modified product inspection model, which is modified from Pulak and Al-Sultan's work, is presented to simultaneously determine the optimum process mean and economic specification limits, based on maximization of the expected total profit per item.
Abstract: Sampling inspection is one of preventive quality methods for decreasing waste of time and cost, but should be along with other quality control approaches to effectively enhance product quality. Det...
TL;DR: The qualitative aspect of the model is revealed, which reveals the fact that queue-length dependent vacation further reduces congestion in the batch-size-dependent bulk service queues.
Abstract: This paper considers a single server finite-buffer batch-size-dependent bulk service queue with queue-length dependent vacation. Customers arrive at the system according to the Poisson process and ...
TL;DR: A new time-between-events chart is presented to monitor the scheduled time using exponentially modified Gaussian distribution and the performance of the chart is evaluated in terms of average run length and coefficient of variation of the run length.
Abstract: Control charts are efficient process monitoring tools used to distinguish between assignable and natural variations. This article presents a new time-between-events chart to monitor the scheduled t...
TL;DR: It is found that under some reasonable condition, this warranty-based linear pricing rule provides an easy way to price the product under a warranty with an appropriate coverage period in practice but also generates almost the maximum profit and capture more market share for the manufacturer.
Abstract: This note focuses on the problem of determining the optimal price and coverage period for warranted products from the manufacturer’s perspective. The goal is to maximize the total profit for a plan...
TL;DR: In this article, a single-level continuous sampling plan (CSP-1) called AOQL contour scheme is constructed on the average outgoing quality limit (AOQL) contour.
Abstract: Single-level continuous sampling plan (CSP-1), called AOQL contour scheme, is constructed on the average outgoing quality limit (AOQL) contour. However, for specified in-control process the boundar...
TL;DR: This paper reformulates the standard OCSVM by a least squares version of the method, which is used to design a control chart for monitoring the mean vector of processes and results indicate that the proposed control chart has very good performances.
Abstract: One-class classification can be thought as a special type of two-class classification problem, where data only from one class, the target class, are available for training the classifier (referred ...
TL;DR: The model in Abdul-Kader et al is modified by incorporating the capability index Cpm to assure the capability of production process and to obtain the process mean, economic specification limits, and quality investment level with minimization of the expected total cost per item.
Abstract: In the present paper, the model in Abdul-Kader et al is modified by incorporating the capability index Cpm to assure the capability of production process and to obtain the process mean, economic sp...
TL;DR: The adaptive EWMA (AEWMA) chart provides better sensitivity than the EWMA chart when detecting mean shifts that lie within a specific interval, and outperforms the existing AEWMA charts when detecting small, moderate and large shifts simultaneously in the process mean.
Abstract: The adaptive EWMA (AEWMA) chart provides better sensitivity than the EWMA chart when detecting mean shifts that lie within a specific interval. In this paper, we propose a novel AEWMA chart for mon...
TL;DR: This paper proposes a density-sensitive novelty weight (DNW) control chart using k-nearest neighbors (kNN) algorithm that can efficiently monitor a process when the distribution of observations is unknown and can fully utilize the in-control local density information.
Abstract: The control chart is one of the most important statistical process control tools and the traditional control charts mostly require a specific probability distribution to set up their control limits...
TL;DR: The proposed Bayesian self-starting monitoring scheme to detect on-line whether a process mean has exceeded a pre-determined critical threshold is shown to be less sensitive to parameter misspecification, more flexible in capturing various trends in the data, and much more computationally efficient.
Abstract: A self-starting process mean monitoring scheme is needed in applications with short production runs or processes subject to degradation. The major challenge in implementing a self-starting monitori...
TL;DR: A Bayesian model for production processes where all produced items are inspected is proposed and the economic superiority of the new scheme is revealed compared to simpler schemes that have been proposed over the years to tackle such problems.
Abstract: Classic approaches of Statistical Process Control (SPC) include the collection of samples from a production process and the computation of some output concerning a specific quality characte...
TL;DR: This paper investigates a discrete-time GI/D-MSP/1/\infty queueing system under N-policy with renewal input and uses the matrix-geometric method to derive the system-length distribution at prearrival epoch and finds the waiting-time distribution in the queue measured in slots of an arrival customer.
Abstract: This paper investigates a discrete-time GI/D-MSP/1/\infty queueing system under N-policy with renewal input. The service process is correlated and its structure is constructed through discrete-time...
TL;DR: The effects of controllable variables on drilling performance are quantified by the face-centered central composite design, and the replacement time of drill bits is optimized using the genetic algorithm.
Abstract: Problem statement: Increasing efficiency and performance of bench drilling in open-pit mines has the potential to generate considerable savings. This increase can be realized by monitoring the dril...
TL;DR: In this article, a fully adaptive multivariate statistical process control scheme for processes where multiple assignable causes may occur is presented, where the assignable cause affects both the mean vector and the variance.
Abstract: This paper presents a fully adaptive multivariate statistical process control scheme for processes where multiple assignable causes may occur. The assignable causes affect both the mean vector and ...