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Shifted log loss Gaussian process model for expected quality loss prediction in robust parameter design Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20210426
Fan Jiang, Matthias HwaiYong TanABSTRACT Robust parameter design (RPD) aims at reducing the effect of noise variation on quality through achieving a small expected quality loss (EQL). In RPD with timeconsuming computer simulations, Gaussian process (GP) models are used to predict the EQL. Three straightforward models for predicting the EQL include a GP model for the simulator output, a GP model for the quality loss, and a lognormal

Integration of marketing and maintenance decisions in twodimensional warranty contracts under a winwin strategy for two transaction sides Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20210412
Ali Salmasnia, Maryam BaratianABSTRACT This study proposes a mathematical model to simultaneous decisionmaking about the marketing and maintenance decisions. Also, a win–win strategy for manufacturer and buyer is established under the twodimensional basic and extended warranty coverages. The product demand and the extended warranty demand are, respectively, considered as functions of the basic and extended warranty regions. To

Determination of Profit Quantification on Kelly Betting Based on Relative Entropy Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20210412
MuEn Wu, ChiaJung Lee, WeiHo Chung, DongYuh YangABSTRACT In 1956, John Kelly formulated an optimal strategy, the socalled ‘Kelly criterion’, for bidding at each step of a favorable game when the odds and probability of winning are known. The Kelly criterion is used to theoretically maximize longrun return. However, in practical situations, it is impossible to play a game for an unlimited time. In this study, we analyze the return of a game when

Optimal design of accelerated degradation test with multiple optimization objectives Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20210408
Jinyan Guo, Zhaojun Yang, Chuanhai Chen, Zhaoming SuABSTRACT In this article, a multiobjective optimization method for the accelerated degradation test is proposed to solve the problem that the single objective optimization cannot meet the needs in practice gradually. Firstly, the Gamma process is assumed to describe the degradation path of product. Then, three optimization objectives are considered to establish the multiobjective optimization model

On the joint distribution of an infinitebuffer discretetime batchsizedependent service queue with single and multiple vacations Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20210329
Nilanjan Nandy, Sourav PradhanABSTRACT Due to the widespread applicability of discretetime queues in wireless networks or telecommunication systems, this paper analyzes an infinitebuffer batchservice queue with single and multiple vacations where customers/messages arrive according to the Bernoulli process and service time varies with the batchsize. The foremost focal point of this analysis is to get the complete joint distribution

Economic design of a CEV x̄ control chart for determining optimal rightcensored times Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20210226
PeiHsi LeeABSTRACT Lifetime is a crucial quality characteristic of electronic products that must be monitored using control charts. Lifetime may provide rightcensored data. A conditional expected value (CEV) x̄ control chart was developed to monitor type I rightcensored data. Researchers had always assumed that the censored time is a known constant when designing control charts. This study provides an economic

Reliability of a retrial system with mixed standby components and Bernoulli vacation Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20201221
Sijia Liu, Linmin Hu, Zhaocai Liu, Yuyu WangABSTRACT This paper studies a K − o u t − o f − N retrial system with mixed standby components and a single repairman under Bernoulli vacation schedule. Such a model is motivated by some machine repair systems in practice. The repairman may either go for a vacation of random length with probability p or stay idle in system with probability 1 − p after the completion of a repair. If a component fails

Modelling and analysis of DBMAP/DMSP/1 queue using RGfactorization Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20201228
K. Das, S. K. SamantaABSTRACT The current investigation of our paper is concentrated on an infinitebuffer singleserver queueing model with discretetime batch Markovian arrival process and Markovian service process. The steadystate behaviour of this discretetime queueing system at various significant time epochs are presented. We first analyze the systemlength distribution at outside observer’s epoch using the R G

Reliability of a retrial system with mixed standby components and Bernoulli vacation Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20201221
Sijia Liu, Linmin Hu, Zhaocai Liu, Yuyu WangABSTRACT This paper studies a K − o u t − o f − N K − o u t − o f − N retrial system with mixed standby components and a single repairman under Bernoulli vacation schedule. Such a model is motivated by some machine repair systems in practice. The repairman may either go for a vacation of random length with probability p p or stay idle in system with probability 1 − p 1 − p after the completion of a

Acceptance sampling schemes for twoparameter Lindley lifetime products under a truncated life test Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20201122
ChienWei Wu, MingHung Shu, NienYun WuABSTRACT In this study, an acceptance sampling plan is developed for a truncated life test when the lifetime of a product follows a twoparameter Lindley distribution. The pairs of required minimum sample size for inspection and the threshold number of failures for lot acceptance are determined for assorted combinations of Lindleydistributed parameters with the enacted termination time of test and

Behavior Analysis of an M/M/1 vacation Queue in Random Environment Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20201117
Sherif AmmarABSTRACT This study examines an M/M/1 vacation queue in a random environment. This system is considered a classical M / M / 1 queueing system in which customers are served one by one in the operative phase i , i = 1 , 2 , … , n , and the arrival and service rates are λ i and μ i . , respectively. The system starts the vacation phase when it is empty and there are no customers to which to provide the

Nonparametric progressive sign chart for monitoring process location based on individual data Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20201015
Zameer Abbas, Hafiz Zafar Nazir, Muhammad Abid, Noureen Akhtar, Muhammad RiazABSTRACT Statistical process control (SPC) plays a vital role in the maintenances and improvements of quality outputs in manufacturing, industrial and service production processes. Control chart is an important SPC tool, used to detect noises and to improve process performance. When the underlying process distribution lacks the assumption of normality, nonparametric (NP) control charts become essential

Joint monitoring of mean and variance using likelihood ratio test statistic with measurement error Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200917
Farah Arif, Muhammad NoorUlAmin, Muhammad HanifABSTRACT This paper explores the effect of measurement errors on a joint monitoring control chart by using three different techniques (i) covariate method (ii) multiple measurements (iii) linear increasing variance. The joint monitoring control chart in the presence of measurement errors are discussed by using an exponentially weighted moving average statistic in the generalized likelihood ratio (GLR)

The triple exponentially weighted moving average control chart Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200913
Vasileios Alevizakos, Kashinath Chatterjee, Christos KoukouvinosQuality control charts are extensively used to monitor processes. The EWMA chart is a good alternative to the Shewhart chart to quickly detect small and moderate shifts in the process mean. The DEWMA charting procedure is an enhanced approach for the EWMA chart and performs much better, especially for small and moderate shifts. In this article, we propose the triple EWMA (TEWMA) chart in an effort

Strategic joining and information disclosing in Markovian queues with an unreliable server and working vacations Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200901
Yu Zhang, Jinting WangWe study a queueing system of an unreliable server providing services to customers with two different service rates. When the system is empty of customers, the server takes a vacation and provides a low service rate. Once the vacation is completed, the server is resumed to serve customers, if any, at a higher service rate, or takes another vacation if the server found an empty system. The server is

On adaptive progressive hybrid censored Burr type III distribution: application to the nano droplet dispersion data Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200827
Hanieh Panahi, Saeid AsadiABSTRACT In the current paper, the maximum likelihood and Bayes estimators for the two shape parameters of the Burr Type III distribution are investigated based on adaptive Type II progressive hybrid censored data. The maximum likelihood estimators are provided for estimating the unknown parameters. The existence and uniqueness of the maximum likelihood estimation are shown using the graphical method

Optimal periodic preventive maintenance policy for a system subject to failures/repairs which follow the nonhomogeneous pure birth process Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200730
YuHung Chien, Zhe George Zhang, Siping Su, SheyHuei SheuThis paper considers a periodic preventive maintenance policy for a deteriorating and repairable system. The system is subject to random failures and is repaired at each failure. To improve the reliability, at periodic times iT (i = 1, 2, … N–1), the system is preventively maintained (PM). At the time NT the system is replaced. The failure/repair process between two PMs follows the NonHomogeneous

On reliability analysis in priority standby redundant systems based on maximum entropy principle Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200730
Ryosuke Hirata, Ikuo Arizono, Yasuhiko TakemotoABSTRACT There are many studies on standby redundant systems, since those are the most standard models for ensuring reliability in systems. Particularly, twocomponent priority standby redundant systems are one of the most fundamental and important redundant models in the reliability theory. In recent years, the procedure for evaluating the mean time to failure (MTTF) of the twocomponent priority

Developing a qualitybased supplier selection model from the buying company perspective Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200630
KuenSuan Chen, Leanne Chung, TsangChuan ChangIn the face of increased competition and globalization, supply chain management has become a crucial aspect of securing competitive advantage. Within this, the quality offered by suppliers is vital. Thus, in this paper, we develop a model to select the best supplier based on process quality from the perspective of the buyer. We first employ the process capability index S p k , which can provide an

New method for prediction of future order statistics Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200630
Haroon M. Barakat, Osama M. Khaled, Hadeer A. GhonemABSTRACT In this paper, we suggest a new efficient method, that yields two new point predictors, for predicting future order statistics, when the sample size remains fixed and when it is enlarged. The two suggested point predictors are constructed based on some characterization properties of order statistics via their distributions. A comprehensive simulation study is conducted on several distributions

A simple procedure for analyzing reliability data from doublestage accelerated life tests Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200616
Xiao LiuABSTRACT This paper proposes a simple statistical approach for analyzing reliability data arising from doublestage Accelerated Life Tests (ALT). The main motivation is to develop a workable solution, which can be easily understood and implemented by quality and reliability engineers, for incorporating existing engineering knowledge on lifestress relationship into ALT data analysis. We focus on the

Reliability and importance measures for a general consecutivetype system Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200524
Frosso S. Makri, Zaharias M. PsillakisABSTRACT A general consecutivetype system, called m consecutive k , ℓ outof n :F system, is considered. Such a system consists of n linearly or circularly ordered components and fails if and only if there are at least m ℓ overlapping runs of k consecutive failed components. For systems with statistically independent components, the system reliability is obtained via recursive schemes and simulation

A networkbased approach to examine the impact of withincity industry agglomeration on total factor productivity Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200519
Zhigang Cai, Ying Li, Yu Yvette ZhangABSTRACT It has been accepted that industry agglomeration has a significant impact on citylevel productivity. However, very few researches have investigated the impact of industry agglomeration from the perspective of spatial distribution of firms and mutual effects between firms. This paper uses a networkbased, withincity approach to shed new light on the impact of industry agglomeration. Based

A networkbased approach to examine the impact of withincity industry agglomeration on total factor productivity Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200519
Zhigang Cai, Ying Li, Yu Yvette ZhangIt has been accepted that industry agglomeration has a significant impact on citylevel productivity. However, very few researches have investigated the impact of industry agglomeration from the perspective of spatial distribution of firms and mutual effects between firms. This paper uses a networkbased, withincity approach to shed new light on the impact of industry agglomeration. Based on a data

Optimal production policy for economic production lotsizing model with preventive maintenance Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200518
Minjae ParkABSTRACT In this study, we determine the optimal manufacturing quantity for an economic production lotsizing model with a defective rate and preventive maintenance for a manufacturing machine. We investigate the properties of economic manufacturing quantity to minimize expected costs during the production run when a random defective rate for that product is considered using an incontrol condition

Equilibrium balking strategies in the singleserver retrial queue with constant retrial rate and catastrophes Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200513
Kaili Li, Jinting WangABSTRACT We study an M/M/1 retrial queueing system with constant retrial rate and Poisson generated catastrophes. When a catastrophe arrives to the system that the server is working, it deletes all customers in system and breaks the server down. The failed server is repaired immediately and the repair time is exponentially distributed. We investigate a joining/balking dilemma of customers with a natural

Matrixgeometric solution of multiserver queueing systems with Bernoulli scheduled modified vacation and retention of reneged customers: A metaheuristic approach Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200506
Chandra Shekhar, Shreekant Varshney, Amit KumarABSTRACT In the present article, we deal with the multiserver finite capacity queueing system with Bernoulli’s scheduled modified vacation policy and the realistic retaining policy of reneged customers. After completion of the service of any customer, the server decides whether to go for the vacation of random duration or to continue facilitating the service to the waiting customer, if any, present

New distributionfree memorytype control charts based on the Wilcoxon ranksum statistic Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200430
JeanClaude MalelaMajikaABSTRACT In this paper, a new distributionfree double exponentially weighted moving average (DEWMA) control chart based on the Wilcoxon ranksum (WRS) test without any distributional assumption of the underlying quality process is proposed. The proposed chart is the extension of the exponentially weighted moving average (EWMA) WRS control chart where the EWMA WRS statistic is applied twice. The ability

Joint optimization and coordination of freshproduct supply chains with qualityimprovement effort and freshkeeping effort Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200419
Bojun Gu, Yufang Fu, Jun YeABSTRACT We consider a freshproduct supply chain (FPSC) in which the supplier and the etailer invest in qualityimprovement effort and freshkeeping effort, respectively. One centralized model and two decentralized models are developed to investigate the optimal effort and pricing decisions for doubleeffort (de), qualityimprovement effort only (qe), freshkeeping effort only (fe) and none effort

A novel local temperature change detection approach in a 3D thermal field Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200409
Yu An, Di Wang, Xi ZhangABSTRACT Local thermal field monitoring is of great importance in industrial engineering practice. In view of the complex thermodynamics of a 3D thermal field, the local temperature change beneath the global thermal field is relatively challenging to detect using existing approaches. To fill this gap, we propose a thermal field monitoring method that decomposes the dynamic thermal field into global

Equilibrium threshold strategies and social benefits in the fully observable Markovian queues with partial breakdowns and interruptible setup/closedown policy Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200311
Amir Aghsami, Fariborz JolaiABSTRACT This paper studies the equilibrium balking strategies in the singleserver Markovian queues with partial breakdowns and interruptible/setup closedown policy. That means the server may fail at any point in time, no matter the server is idle or busy and the service continues at a slower rate instead of stopping service totally. When the system becomes empty, the server ceases to operate by a

A new Bayesian scheme for selfstarting process mean monitoring Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200224
Yuxing Hou, Baosheng He, Xudong Zhang, Yong Chen, Qingyu YangABSTRACT A selfstarting process mean monitoring scheme is needed in applications with short production runs or processes subject to degradation. The major challenge in implementing a selfstarting monitoring scheme is that there exists little or no historical incontrol data to accurately estimate incontrol process parameters. In this paper, we propose a new Bayesian selfstarting monitoring scheme

The integrated quality control model with product inspection and process improvement Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200213
ChungHo Chen, ChaoYu ChouABSTRACT 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. Determination of optimum process mean tends to reduce the bias of the central tendency of process characteristic from its target, and has been an important topic in quality system design. Pulak and

The integrated study for process improvement with economic specification limits, process means setting and quality investment: an extension of the model in AbdulKader et al. (2010) Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200130
ChungHo Chen, ChaoYu ChouABSTRACT In the present paper, the model in AbdulKader 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. Three modified models are presented and discussed, where Model I firstly determines the optimal

Change detection using least squares oneclass classification control chart Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20200110
Edgard M. MaboudouTchaoOneclass classification can be thought as a special type of twoclass classification problem, where data only from one class, the target class, are available for training the classifier (referred to as oneclass classifier). The problem of classifying positive (or target) cases in the absence of appropriately characterized negative cases (or outliers) has gained increasing attention in recent years

Monitoring location and scale of multivariate processes subject to a multiplicity of assignable causes Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20191221
Konstantinos A. Tasias, George NenesThis 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 the covariance matrix, monitored by a T 2 chart and a control chart based on entropy, respectively. Markov chain theory is employed to model the stochastic operation of the proposed scheme and optimize its

Economicstatistical design of variable parameters s chart Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20191206
Ming Ha Lee, Michael B. C. Khoo, Xinying ChewIn this paper, the economicstatistical design of the variable parameters (VP) s chart is investigated, where all the design parameters of the s chart are allowed to vary between two values as a function of the most recent process information. The optimal design parameters of the VP s chart are derived based on the economic and statistical criteria. The economicstatistical design is performed by minimizing

A modifiedmxEWMA location chart for the improved process monitoring using auxiliary information and its application in wood industry Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20191206
Syed Masroor Anwar, Muhammad Aslam, Shabbir Ahmad, Muhammad RiazIn this paper, we have proposed a new modified Exponentially Weighted Moving Average location control chart named as a modifiedmxEWMA chart. The newly proposed chart uses the information of an auxiliary variable to improve the shift detection ability. The control structure of the modifiedmxEWMA chart is developed and important measures such as ARL, SDRL, EQL, PCI, and RARL are computed to assess

Designing an accelerated degradation test plan considering the gamma degradation process with multistress factors and interaction effects Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20191203
Shah Limon, Esmaeil Rezaei, Om Prakash YadavThe effectiveness of accelerated degradation test and subsequent reliability assessment depends on the efficient test plan. Designing an accelerated test plan requires determining the optimal values of several decision variables. The problem of designing an accelerated degradation test becomes even more challenging when multiple stress factors and their interaction effects are considered. In this work

A parameterfree adaptive EWMA mean chart Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20191110
Abdul Haq, Michael B. C. KhooThe 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 monitoring the mean of a normally distributed process. The proposed AEWMA chart is parameterfree apart from its decision interval, which makes it very easy to implement, and at the same time, it provides balanced

DP Pareto optimal balanced orthogonal subplot designs Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20191103
Shaun S. Wulff, Yongtao Cao, Timothy J. RobinsonThis paper considers the problem of identifying optimal SplitPlot Designs (SPDs) using traditional design criteria along with pure error degrees of freedom. An optimal SPD is of little use if it does not allow for suitable variance estimation of the whole plot and subplot variance components. The proposed approach incorporates a multicriterion version of DPoptimality to represent the conflicting

On finitebuffer batchsizedependent bulk service queue with queuelength dependent vacation Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20191103
G. K. Gupta, A. Banerjee, U. C. GuptaThis paper considers a single server finitebuffer batchsizedependent bulk service queue with queuelength dependent vacation. Customers arrive at the system according to the Poisson process and are served in batches of maximum size ‘b’ with a minimum threshold value ‘a’ following the ‘general bulk service’ rule. The service time distribution is assumed to be of general type which modulates depending

An EWMA and region growing based control chart for monitoring image data Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20191030
Ling Zuo, Zhen He, Min ZhangThe widespread application of machine vision system promotes the development of imagebased statistical process control methodologies to improve the utilization of image data. Previous research has focused on either identification of fault size and/or location or detection of fault occurrence. There is limited research on both fault detection and identification. In this paper, an EWMA and region growing

Monitoring schedule time using exponentially modified Gaussian distribution Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190926
Jehan Ara, Sajid Ali, Ismail ShahControl charts are efficient process monitoring tools used to distinguish between assignable and natural variations. This article presents a new timebetweenevents chart to monitor the scheduled time. In particular, exponentially modified Gaussian distribution is considered in the construction of the control chart. The performance of the chart is evaluated in terms of average run length and coefficient

Performance analysis of the GI/DMSP/1 queue with Npolicy and its optimal control Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190923
S. K. Samanta, R. NandiThis paper investigates a discretetime GI/DMSP/1/\infty queueing system under Npolicy with renewal input. The service process is correlated and its structure is constructed through discretetime Markovian service process. The idle server resumes to serve the customers as soon as the number of waiting customers in the queue reaches a predefined threshold value N and serves the customers exhaustively

A robust alternate to the HEWMA control chart under nonnormality Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190917
Azaz Ahmed, Aamir Sanaullah, Muhammad HanifIn 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 affected if quality characteristics depart from normality or have the presence of outliers. For such situations, a new robustHEWMA control chart is proposed for the scenario in which quality characteristics

A comparative study on Poisson control charts Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190811
Vasileios Alevizakos, Christos KoukouvinosIn 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 different control charts have been developed. In this article, we compare the performance of several widely used Poisson control charts in terms of the average runlength. Based on the comparison study, some

The effects of model misspecification on shelflife prediction of nanosols under pH acceleration Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190626
ShengTsaing Tseng, YuCheng Yao, David Shan Hill WongShelflife prediction of liquidtype (such as nanosol) products is an interesting research topic. Recently, a pH acceleration method has been proposed in the literature to address the shelflife prediction of nanosol. The time evolution of particlesize distribution was obtained and modelled. There are two approaches for modelling the particlesize distribution, either by using a parametric approach

Distributed outlier detection in hierarchically structured datasets with mixed attributes Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190621
Qiao Liang, Kaibo WangAnomaly detection has been extensively studied over the past decades; however, there are still various challenges due to the complex structures of the realworld datasets. First, only a few methods in the literature provide insight into the datasets that have both categorical and continuous attributes, and even fewer of them are sensitive to the dependencies between the two types of attributes. Second

A decisionmaking framework for evaluating enterprise resource planning systems in a hightech industry Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190613
Amy H. I. Lee, ShunChien Chen, HeYau KangIn recent years, the adoption of enterprise resource planning (ERP) is becoming essential for achieving fast and transparent information exchange, avoiding unnecessary waste and maintaining coordination within a firm and among partners in a supply chain. However, the implementation of an ERP system often fails, and one major reason is that the selected ERP system is not suitable for the firm. Therefore

Conditional analysis of Phase II exponential chart for monitoring times to an event Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190528
Nirpeksh KumarIt 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 characteristics of unconditional run length (URL) distribution. However, it is now under criticism because the unconditional analysis based on URL does not give the full impression of the chart’s performance conditioning

Optimization analysis of management operation for a server farm Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190519
FuMin ChangThis paper analyses a server farm with a simple management operation, which is desirable to reduce power consumption. A block of servers is named as ‘reserves’. Depending on the number of jobs staying in the system, powerup and powerdown thresholds are employed to control the state of the reserves. In addition, the process of powerup is not immediately. During the period, the servers cannot serve

Monitoring the process location by using new ranked set samplingbased memory control charts Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20190222
Tahir Nawaz, Dong HanThe 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 and inexpensive method of obtaining a more representative sample when the actual quantification of sampling units is expensive or destructive, while the ranking of the observations is easier. In this paper

Statistical effects of waterway lock unavailability on commodity flow Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20181114
Justin R. Chimka, Adrian Fernandez De Luis, Grace W. McGeeProblem statement: It has been posited that insufficient funding for lock maintenance on the inland waterway system causes scheduled and unscheduled delays that greatly threaten inland waterway system performance. We seek to express this in a concrete form and explore quantitatively the extent to which it may be true. Approach: Our approach is to estimate statistical models using Lock Use, Performance

Socioeconomic design of control charts for monitoring service processes: a case study of a restaurant system Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20181107
Mohsen Ebadi, Amir AhmadiJavidThe main purpose of this paper is to design a control chart for monitoring the service processes in congested immobile singlestage service systems where customer arrivals are time dependent. It is investigated how social and economic/statistical aspects of the control chart can be addressed. As customer satisfaction is a key success factor for a service system, our proposed design method incorporates

Service quality variation monitoring using the interquartile range control chart Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20181002
SuFen Yang, TingAn JiangControl charts are effective tools for signal detection for both manufacturing and service processes. Much of the data in service industries come from processes exhibiting nonnormal or unknown distributions, for which Shewhart variables control charts are not appropriate. This paper thus proposes a new exponentially weighted moving average (EWMA) interquartile range control chart with single sampling

A reevaluation of the run rules xbar chart when the process parameters are unknown Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20181002
XueLong Hu, Philippe CastagliolaRun Rules Xˉ chart are often implemented for process monitoring. The process observations are usually assumed normally distributed, and the process parameters are assumed known. In fact, a very limited number of Phase I samples may only be available to the practitioners to estimate the process parameters, the control chart's properties will vary among different practitioners. Considering this variability

Analysis of a single server batch arrival unreliable queue with balking and general retrial time Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20180905
Djamila Zirem, Mohamed Boualem, Karima AdelAissanou, Djamil AïssaniThis paper deals with a batch arrivals queue with general retrial time, breakdowns, repairs and reserved time. Here we assume that customers arrive according to compound Poisson processes. Any arriving batch of primary customers finds the server free, one of the customers from the batch enters into the service area and the rest of them join into the orbit. The primary customers who find the server

Postwarranty maintenance optimization for products with deterioration depending on aging and shock Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20180821
Lijun Shang, Zhiqiang Cai, Hudong Chen, Shuai ZhangDue to the nonsubstitutability of the product, the monopoly manufacturer designs warranty to reduce maximally warranty cost. Although the monopoly manufacturer maintains responsibly product reliability in warranty, the consumer still confronts a problem about how to sustain product reliability after the designed warranty expires. Goal of this paper is, from the consumer’s perspective, to propose a

Design of control charts for multivariate Poisson distribution using generalized multiple dependent state sampling Qual. Technol. Quant. Manag. (IF 2.231) Pub Date : 20180810
Muhammad Ali Raza, Muhammad AslamIn this paper, two attribute control charts under multiple dependent state sampling (MDS) and its modification are proposed to monitor the multivariate Poisson count data. The sensitivity of the MDS is increased by introducing an additional parameter. The new method is named as generalized multiple dependent state sampling (GMDS). The proposed charts are based on two pairs of limits i.e. inner and