http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Tue, 04 Dec 2012 14:13:11 +0000 http://www.hindawi.com/journals/ijqsr/2012/870984/ The probability theory, in general, with the help of the dichotomous state develops the theory of reliability. Recently, the fuzzy reliability has been developed based on the concept of possibility distribution and fuzzy-state assumption. In this paper, we derive the possibility distribution function and discuss the properties of a -out-of- () system based on the assumption of the possibility theory and keeping the dichotomous state of the system unchanged when the lifetime distribution is either normal, Cauchy, or exponential. A few results contrary to the conventional reliability theory are obtained. Subarna Bhattacharjee, Asok K. Nanda, and S. S. Alam Copyright © 2012 Subarna Bhattacharjee et al. All rights reserved. Wed, 28 Nov 2012 15:53:29 +0000 http://www.hindawi.com/journals/ijqsr/2012/675830/ A parameter estimation problem for a backup system in a condition-based maintenance is considered. We model a backup system by a hidden, three-state continuous time Markov process. Data are obtained through condition monitoring at discrete time points. Maximum likelihood estimates of the model parameters are obtained using the EM algorithm. We establish conditions under which there is no more than one limitation in the parameter space for any sequence derived by the EM algorithm. Qihong Duan, Ying Wei, and Xiang Chen Copyright © 2012 Qihong Duan et al. All rights reserved. Sun, 25 Nov 2012 09:36:08 +0000 http://www.hindawi.com/journals/ijqsr/2012/248146/ This paper includes the Bayesian analysis of Burr type VII distribution. Three censoring schemes, namely, left censoring, singly type II censoring, and doubly type II censoring have been used for posterior estimation. The results of different censoring schemes have been compared with those under complete samples. The comparative study among the performance of different censoring schemes has also been made. Two noninformative (uniform and Jeffreys) priors have been assumed to derive the posterior distributions under each case. The performance of Bayes estimators has been compared in terms of posterior risks under a simulation study. Navid Feroze and Muhammad Aslam Copyright © 2012 Navid Feroze and Muhammad Aslam. All rights reserved. Wed, 14 Nov 2012 15:05:48 +0000 http://www.hindawi.com/journals/ijqsr/2012/203842/ Reliability, availability, and maintainability (RAM) analysis has helped to identify the critical and sensitive subsystems in the production systems that have a major effect on system performance. But the collected or available data, reflecting the system failure and repair patterns, are vague, uncertain, and imprecise due to various practical constraints. Under these circumstances it is difficult, if not possible, to analyze the system performance up to desired degree of accuracy. For this, Artificial Bee Colony based Lambda-Tau (ABCBLT) technique has been used for computing the RAM parameters by utilizing uncertain data up to a desired degree of accuracy. Results obtained are compared with the existing Fuzzy Lambda-Tau results and we conclude that proposed results have a less range of uncertainties. Also ranking the subcomponents for improving the performance of the system has been done using RAM-Index. The approach has been illustrated through analyzing the performance of the screening unit of a paper industry. Harish Garg, Monica Rani, and S. P. Sharma Copyright © 2012 Harish Garg et al. All rights reserved. Thu, 08 Nov 2012 16:21:03 +0000 http://www.hindawi.com/journals/ijqsr/2012/617481/ When dealing with complex systems, all decision making occurs under some level of uncertainty. This is due to the physical attributes of the system being analyzed, the environment in which the system operates, and the individuals which operate the system. Techniques for decision making that rely on traditional probability theory have been extensively pursued to incorporate these inherent aleatory uncertainties. However, complex problems also typically include epistemic uncertainties that result from lack of knowledge. These problems are fundamentally different and cannot be addressed in the same fashion. In these instances, decision makers typically use subject matter expert judgment to assist in the analysis of uncertainty. The difficulty with expert analysis, however, is in assessing the accuracy of the expert's input. The credibility of different information can vary widely depending on the expert’s familiarity with the subject matter and their intentional (i.e., a preference for one alternative over another) and unintentional biases (heuristics, anchoring, etc.). This paper proposes the metric of evidential credibility to deal with this issue. The proposed approach is ultimately demonstrated on an example problem concerned with the estimation of aircraft maintenance times for the Turkish Air Force. Patrick Hester Copyright © 2012 Patrick Hester. All rights reserved. Tue, 23 Oct 2012 16:15:03 +0000 http://www.hindawi.com/journals/ijqsr/2012/847416/ Fuzzy sets membership functions integrated with logistic map as the chaos generator were used to create reliability bifurcations diagrams of the system with redundancy of the components. This paper shows that increasing in the number of redundant components results in a postponement of the moment of the first bifurcation which is considered as most contributing to the loss of the reliability. The increasing of redundancy also provides the shrinkage of the oscillation orbit of the level of the system’s membership to reliable state. The paper includes the problem statement of redundancy optimization under conditions of chaotic behavior of influencing parameters and genetic algorithm of this problem solving. The paper shows the possibility of chaos-tolerant systems design with the required level of reliability. Alexander Rotshtein, Denys Katielnikov, and Ludmila Pustylnik Copyright © 2012 Alexander Rotshtein et al. All rights reserved. Thu, 11 Oct 2012 11:23:57 +0000 http://www.hindawi.com/journals/ijqsr/2012/287582/ This paper proposes a distribution-free (or nonparametric) control scheme to monitor a process output that contains two special causes of variation called “block or batch” effects and “treatment or position” effects. The scheme properties (control limits, false alarm rate, and in-control average run length) stay the same under any assumed continuous probability distribution. For moderate sample sizes, these properties can be computed exactly from available tables without the need to estimate the mean or variance of the process. The proposed monitoring scheme requires ranking the observations within blocks and using the method of analysis of means by ranks. The paper includes an illustrative example concerning the grinding process of silicon wafers used in integrated circuits production. Saad T. Bakir Copyright © 2012 Saad T. Bakir. All rights reserved. Tue, 11 Sep 2012 13:26:44 +0000 http://www.hindawi.com/journals/ijqsr/2012/147520/ This paper develops a distribution-free (or nonparametric) Shewhart-type statistical quality control chart for detecting a broad change in the probability distribution of a process. The proposed chart is designed for grouped observations, and it requires the availability of a reference (or training) sample of observations taken when the process was operating in-control. The charting statistic is a modified version of the two-sample Kolmogorov-Smirnov test statistic that allows the exact calculation of the conditional average run length using the binomial distribution. Unlike the traditional distribution-based control charts (such as the Shewhart X-Bar), the proposed chart maintains the same control limits and the in-control average run length over the class of all (symmetric or asymmetric) continuous probability distributions. The proposed chart aims at monitoring a broad, rather than a one-parameter, change in a process distribution. Simulation studies show that the chart is more robust against increased skewness and/or outliers in the process output. Further, the proposed chart is shown to be more efficient than the Shewhart X-Bar chart when the underlying process distribution has tails heavier than those of the normal distribution. Saad T. Bakir Copyright © 2012 Saad T. Bakir. All rights reserved. Wed, 08 Aug 2012 10:47:08 +0000 http://www.hindawi.com/journals/ijqsr/2012/897106/ The three-parameter lognormal distribution is the extension of the two-parameter lognormal distribution to meet the need of the biological, sociological, and other fields. Numerous research papers have been published for the parameter estimation problems for the lognormal distributions. The inclusion of the location parameter brings in some technical difficulties for the parameter estimation problems, especially for the interval estimation. This paper proposes a method for constructing exact confidence intervals and exact upper confidence limits for the location parameter of the three-parameter lognormal distribution. The point estimation problem is discussed as well. The performance of the point estimator is compared with the maximum likelihood estimator, which is widely used in practice. Simulation result shows that the proposed method is less biased in estimating the location parameter. The large sample size case is discussed in the paper. Zhenmin Chen and Feng Miao Copyright © 2012 Zhenmin Chen and Feng Miao. All rights reserved. Thu, 26 Jul 2012 14:10:10 +0000 http://www.hindawi.com/journals/ijqsr/2012/494818/ An important problem encountered in product or process design is the setting of process variables to meet a required specification of quality characteristics (response variables), called a multiple response optimization (MRO) problem. Common optimization approaches often begin with estimating the relationship between the response variable with the process variables. Among these methods, response surface methodology (RSM), due to simplicity, has attracted most attention in recent years. However, in many manufacturing cases, on one hand, the relationship between the response variables with respect to the process variables is far too complex to be efficiently estimated; on the other hand, solving such an optimization problem with accurate techniques is associated with problem. Alternative approach presented in this paper is to use artificial neural network to estimate response functions and meet heuristic algorithms in process optimization. In addition, the proposed approach uses the Taguchi robust parameter design to overcome the common limitation of the existing multiple response approaches, which typically ignore the dispersion effect of the responses. The paper presents a case study to illustrate the effectiveness of the proposed intelligent framework for tackling multiple response optimization problems. Ali Salmasnia, Mahdi Bastan, and Asghar Moeini Copyright © 2012 Ali Salmasnia et al. All rights reserved. Thu, 05 Jul 2012 14:53:03 +0000 http://www.hindawi.com/journals/ijqsr/2012/176270/ In this work, Probabilistic Safety Assessment (PSA) is used to evaluate Allowed Outage Times (AOT) and Surveillance Test Intervals (STI) extensions for three Angra 1 nuclear power plant safety systems. The interest in such an analysis lies on the fact that PSA comprises a risk-based tool for safety evaluation and has been increasingly applied to support both the regulatory and the operational decision-making processes. Regarding Angra 1, among other applications, PSA is meant to be an additional method that can be used by the utility to justify Technical Specification relaxation to the Brazilian regulatory body. The risk measure used in this work is the Core Damage Frequency, obtained from the Angra 1 Level 1 PSA study. AOT and STI extensions are evaluated for the Safety Injection, Service Water and Auxiliary Feedwater Systems using the SAPHIRE code. In order to compensate for the risk increase caused by the extensions, compensatory measures as (1) test of redundant train prior to entering maintenance and (2) staggered test strategy are proposed. Results have shown that the proposed AOT extensions are acceptable for two of the systems with the implementation of compensatory measures whereas STI extensions are acceptable for all three systems. Sonia M. Orlando Gibelli, P. F. Frutuoso e Melo, and Sérgio Q. Bogado Leite Copyright © 2012 Sonia M. Orlando Gibelli et al. All rights reserved. Sun, 13 May 2012 13:24:44 +0000 http://www.hindawi.com/journals/ijqsr/2012/760687/ A four-parameter family of Weibull distributions is introduced, as an example of a more general class created along the lines of Marshall and Olkin, 1997. Various properties of the distribution are explored and its usefulness in modelling real data is demonstrated using maximum likelihood estimates. Vasileios Pappas, Konstantinos Adamidis, and Sotirios Loukas Copyright © 2012 Vasileios Pappas et al. All rights reserved. Thu, 05 Apr 2012 16:03:23 +0000 http://www.hindawi.com/journals/ijqsr/2012/481538/ This study addresses spatial effects by applying spatial analysis in studying whether household economic status (HES) is related to health across governorates in Iraq. The aim is to assess variation in health and whether this variation is accounted for by variation in HES. A spatial univariate and bivariate autocorrelation measures were applied to cross-sectional data from census conducted in 2004. The hypothesis of spatial clustering for HES was confirmed by a positive global Moran’s 𝐼 of 0.28 with 𝑃=0.010, while for health was not confirmed by a negative global Moran’s 𝐼 of −0.03. Based on local Moran’s 𝐼𝑖, two and seven significant clusters in health and in HES were found respectively. Bivariate spatial correlation between health and HES wasn’t found significant (𝐼𝑥𝑦=−0.08) with 𝑃=0.80. In conclusion, geographical variation was found in each of health and HES. Based on visual inspection, the patterns formed by governorates with lowest health and those with lowest HES were partly identical. However, this study cannot support the hypothesis that variation in HES may spatially explain variation in health. Further research is needed to understand mechanisms underlying the influence of neighbourhood context. Faisal G. Khamis Copyright © 2012 Faisal G. Khamis. All rights reserved. Wed, 08 Feb 2012 09:08:43 +0000 http://www.hindawi.com/journals/ijqsr/2012/985152/ We propose an asymptotic nonparametric confidence interval for quantile-based process capability indices (PCIs) based on the superstructure 𝐶𝑁𝑝(𝑢,𝑣) modified from 𝐶𝑝(𝑢,𝑣) which contains the four basic PCIs, 𝐶𝑝, 𝐶𝑝𝑘, 𝐶𝑝𝑚, and 𝐶𝑝𝑚𝑘, as special cases. Since the asymptotic variance of the estimator for quantile-based PCIs involves the density function of the underlying process, the existing asymptotic results cannot be used directly to construct confidence limits for PCIs. To obtain a consistent estimator for the asymptotic variance of the estimated quantile-based PCIs, in this paper, we propose to use the kernel density estimator for the underlying process. Consequently, the confidence limits for PCIs are established based on the consistent estimates. A real-life example from manufacturing engineering is used to illustrate the implementation of the proposed methods. Simulation studies are also presented in this paper to compare the two quantile estimators that are used in the definition of PCIs. Cheng Peng and Jiaqing Xu Copyright © 2012 Cheng Peng and Jiaqing Xu. All rights reserved. Tue, 17 Jan 2012 11:10:53 +0000 http://www.hindawi.com/journals/ijqsr/2011/830764/ Multivariate analysis is increasingly used to include all dimensions of quality concept, in light of rapid development of customer requirements. With the recent advances in information technology and in recording, large amounts of multivariate data are now needed to be analyzed. Many charting procedures are based on Mahalanobis distance, but their applicability relies heavily on the requirement of normality and their performance is related to the choice of a type I error rate. An alternative charting scheme based on data depth is pursued and its performance is assessed through a real example. This performance and that of a 𝑇2 chart for individual observations are discussed. Using the centre-outward ranking, this new method named DD-diagram is used to detect any multivariate quality datum that one of its components exceeds its limiting variation interval. For a given error-free sample, the DD-diagram can be used to signal out any point of another observed sample taken from a multivariate quality process. This new scheme based on data depth uses a properly chosen limiting variation line or 𝐿value in order to evaluate the outlyingness of every point in the observed sample in all directions of the considered 𝑃-variates of quality process. Mekki Hajlaoui Copyright © 2011 Mekki Hajlaoui. All rights reserved. Sun, 20 Nov 2011 10:13:01 +0000 http://www.hindawi.com/journals/ijqsr/2011/379129/ Reliability studies for coding contributing factors of incident reports in high hazard industries are rarely conducted and reported. Although the Human Factors Analysis and Classification System (HFACS) appears to have a larger number of such studies completed than most other systems doubt exists as the accuracy and comparability of results between studies due to aspects of methodology and reporting. This paper reports on a trial conducted on HFACS to determine its reliability in the context of military air traffic control (ATC). Two groups participated in the trial: one group comprised of specialists in the field of human factors, and the other group comprised air traffic controllers. All participants were given standardized training via a self-paced workbook and then read 14 incident reports and coded the associated findings. The results show similarly low consensus for both groups of participants. Several reasons for the results are proposed associated with the HFACS model, the context within which incident reporting occurs in real organizations and the conduct of the studies. Liang Wang, Yaohua Wang, Xiaoqiang Yang, Kai Cheng, Haishan Yang, Baoguo Zhu, Chengfei Fan, and Xinwei Ji Copyright © 2011 Liang Wang et al. All rights reserved. Thu, 03 Nov 2011 11:13:05 +0000 http://www.hindawi.com/journals/ijqsr/2011/820243/ Microelectromechanical systems (MEMS) are a fast-growing field in microelectronics. MEMS are commonly used as actuators and sensors with a wide variety of applications in health care, automotives, and the military. The MEMS production cycle can be classified as three basic steps: (1) design process, (2) manufacturing process, and (3) operating cycle. Several studies have been conducted for steps (1) and (2); however, information regarding operational failure modes in MEMS is lacking. This paper discusses reliability in the context of MEMS functionality. It also presents a brief review of the most relevant failure mechanisms for MEMS. Daniel J. Fonseca and Miguel Sequera Copyright © 2011 Daniel J. Fonseca and Miguel Sequera. All rights reserved. Mon, 19 Sep 2011 14:02:28 +0000 http://www.hindawi.com/journals/ijqsr/2012/245910/ This paper considers the estimation problem for the Frèchet distribution under progressive Type II censoring with random removals, where the number of units removed at each failure time has a binomial distribution. We use the maximum likelihood method to obtain the estimators of parameters and derive the sampling distributions of the estimators, and we also construct the confidence intervals for the parameters and percentile of the failure time distribution. Mohamed Mubarak Copyright © 2012 Mohamed Mubarak. All rights reserved. Tue, 06 Sep 2011 14:40:50 +0000 http://www.hindawi.com/journals/ijqsr/2011/537543/ One of the key issues in robust parameter design is to configure the controllable factors to minimize the variance due to noise variables. However, it can sometimes happen that the number of control variables is greater than the number of noise variables. When this occurs, two important situations arise. One is that the variance due to noise variables can be brought down to zero The second is that multiple optimal control variable settings become available to the experimenter. A simultaneous confidence region for such a locus of points not only provides a region of uncertainty about such a solution, but also provides a statistical test of whether or not such points lie within the region of experimentation or a feasible region of operation. However, this situation requires a confidence region for the multiple-solution factor levels that provides proper simultaneous coverage. This requirement has not been previously recognized in the literature. In the case where the number of control variables is greater than the number of noise variables, we show how to construct critical values needed to maintain the simultaneous coverage rate. Two examples are provided as a demonstration of the practical need to adjust the critical values for simultaneous coverage. Aili Cheng, John Peterson, and Pallavi Chitturi Copyright © 2011 Aili Cheng et al. All rights reserved. Thu, 25 Aug 2011 08:12:44 +0000 http://www.hindawi.com/journals/ijqsr/2011/681210/ This paper deals with the Bayes prediction of the future failures of a deteriorating repairable mechanical system subject to minimal repairs and periodic overhauls. To model the effect of overhauls on the reliability of the system a proportional age reduction model is assumed and the 2-parameter Engelhardt-Bain process (2-EBP) is used to model the failure process between two successive overhauls. 2-EBP has an advantage over Power Law Process (PLP) models. It is found that the failure intensity of deteriorating repairable systems attains a finite bound when repeated minimal repair actions are combined with some overhauls. If such a data is analyzed through models with unbounded increasing failure intensity, such as the PLP, then pessimistic estimates of the system reliability will arise and incorrect preventive maintenance policy may be defined. On the basis of the observed data and of a number of suitable prior densities reflecting varied degrees of belief on the failure/repair process and effectiveness of overhauls, the prediction of the future failure times and the number of failures in a future time interval is found. Finally, a numerical application is used to illustrate the advantages from overhauls and sensitivity analysis of the improvement parameter carried out. Preeti Wanti Srivastava and Nidhi Jain Copyright © 2011 Preeti Wanti Srivastava and Nidhi Jain. All rights reserved. Thu, 18 Aug 2011 11:13:55 +0000 http://www.hindawi.com/journals/ijqsr/2011/721962/ The reliability function for a parallel system of two identical components is derived from a stress-strength model, where failure of one component increases the stress on the surviving component of the system. The Maximum Likelihood Estimators of parameters and their asymptotic distribution are obtained. Further the Maximum Likelihood Estimator and Bayes Estimator of reliability function are obtained using the data from a life-testing experiment. Computation of estimators is illustrated through simulation study. S. B. Munoli and Rohit R. Mutkekar Copyright © 2011 S. B. Munoli and Rohit R. Mutkekar. All rights reserved. Tue, 09 Aug 2011 14:36:40 +0000 http://www.hindawi.com/journals/ijqsr/2011/396297/ We evaluate the ability of transient response analysis method (TRAM), a simple test strategy proposed for filters, to detect deviations in circuit specifications beyond established limits. Particularly, we focus our attention on deviations produced by displacement damage in integrated resistors. This damage is produced by the impact of high-energy particles like the encountered in space environments. For this purpose, we formulate a simple deviation-fault model that takes into consideration the degradation addressed. Additionally, more transient response parameters are taken into account in order to improve the fault coverage. We adopt for our evaluations two typical second-order filters as cases of study. For these filters, the simulation results show that TRAM reaches excellent fault coverage for both filters, suggesting that its use in space applications is encouraging. José Peralta, Gabriela Peretti, Eduardo Romero, Gustavo Demarco, and Carlos Marqués Copyright © 2011 José Peralta et al. All rights reserved. Thu, 04 Aug 2011 10:39:42 +0000 http://www.hindawi.com/journals/ijqsr/2011/395034/ A sequence of independent lifetimes 𝑋1,…,𝑋𝑚,𝑋𝑚+1,…,𝑋𝑛 was observed from Maxwell distribution with reliability 𝑟1(𝑡) at time 𝑡 but later, it was found that there was a change in the system at some point of time 𝑚 and it is reflected in the sequence after 𝑋𝑚 by change in reliability 𝑟2(𝑡) at time 𝑡. The Bayes estimators of 𝑚, 𝜃1, 𝜃2 are derived under different asymmetric loss functions. The effects of correct and wrong prior information on the Bayes estimates are studied. Mayuri Pandya and Hardik Pandya Copyright © 2011 Mayuri Pandya and Hardik Pandya. All rights reserved. Wed, 27 Jul 2011 16:12:25 +0000 http://www.hindawi.com/journals/ijqsr/2011/637079/ This paper considers three competing maintenance actions: corrective after failure, condition-based preventive to avoid failure, and scheduled. A stochastic model is set for the time relationship between corrective and preventive maintenance. This model defines a version of the so-called random signs censoring, and it leads to natural goodness measures for condition control. The effect of condition control on important observable and unobservable indicators is studied. The latter half of the paper considers static Weibull models for the time to failure and the effect of condition control; the main contribution is a calculation method that derives the four model parameters from four figures of input data. Corresponding parameter experimentation is demonstrated on maintenance cost analysis and condition control design. Per-Erik Hagmark Copyright © 2011 Per-Erik Hagmark. All rights reserved. Tue, 26 Jul 2011 13:12:15 +0000 http://www.hindawi.com/journals/ijqsr/2011/357814/ Let the regression model be 𝑌𝑖=𝛽1𝑋𝑖+𝜀𝑖, where 𝜀𝑖 are i. i. d. N (0,𝜎2) random errors with variance 𝜎2>0 but later it was found that there was a change in the system at some point of time 𝑚 and it is reflected in the sequence after 𝑋𝑚 by change in slope, regression parameter 𝛽2. The problem of study is when and where this change has started occurring. This is called change point inference problem. The estimators of 𝑚, 𝛽1,𝛽2 are derived under asymmetric loss functions, namely, Linex loss & General Entropy loss functions. The effects of correct and wrong prior information on the Bayes estimates are studied. Mayuri Pandya, Krishnam Bhatt, and Paresh Andharia Copyright © 2011 Mayuri Pandya et al. All rights reserved. Sun, 15 May 2011 14:29:08 +0000 http://www.hindawi.com/journals/ijqsr/2011/718901/ A methodology for probabilistic modeling of fatigue damage accumulation for single stress level and multistress level loading is proposed in this paper. The methodology uses linear damage accumulation model of Palmgren-Miner, a probabilistic 𝑆-𝑁 curve, and an approach for a one-to-one transformation of probability density functions to achieve the objective. The damage accumulation is modeled as a nonstationary process as both the expected damage accumulation and its variability change with time. The proposed methodology is then used for reliability prediction under single stress level and multistress level loading, utilizing dynamic statistical model of cumulative fatigue damage. The reliability prediction under both types of loading is demonstrated with examples. Vijay Rathod, Om Prakash Yadav, Ajay Rathore, and Rakesh Jain Copyright © 2011 Vijay Rathod et al. All rights reserved. Wed, 11 May 2011 13:36:21 +0000 http://www.hindawi.com/journals/ijqsr/2011/618347/ We derive Bayes estimators of reliability and the parameters of a two- parameter geometric distribution under the general entropy loss, minimum expected loss and linex loss, functions for a noninformative as well as beta prior from multiply Type II censored data. We have studied the robustness of the estimators using simulation and we observed that the Bayes estimators of reliability and the parameters of a two-parameter geometric distribution under all the above loss functions appear to be robust with respect to the correct choice of the hyperparameters 𝑎(𝑏) and a wrong choice of the prior parameters 𝑏(𝑎) of the beta prior. J. B. Shah and M. N. Patel Copyright © 2011 J. B. Shah and M. N. Patel. All rights reserved. Sun, 27 Feb 2011 16:01:48 +0000 http://www.hindawi.com/journals/ijqsr/2011/719534/ Since Lindley and Smith introduced the idea of hierarchical prior distribution, some results have been obtained on hierarchical Bayesian method to deal with lifetime data. But all those results obtained by means of hierarchical Bayesian methods involve complicated integration compute. Though some computing methods such as Markov Chain Monte Carlo (MCMC) are available, doing integration is still very inconvenient for practical problems. This paper introduces a new method, named E-Bayesian estimation method, to estimate failure probability. In the case of one hyperparameter, the definition of E-Bayesian estimation of the failure probability is provided; moreover, the formulas of E-Bayesian estimation and hierarchical Bayesian estimation and the property of E-Bayesian estimation of the failure probability are also provided. Finally, calculation on practical problems shows that the provided method is feasible and easy to perform. Ming Han Copyright © 2011 Ming Han. All rights reserved. Tue, 15 Feb 2011 15:56:04 +0000 http://www.hindawi.com/journals/ijqsr/2010/816407/ Steering module is a part of automotive suspension system which provides a means for an accurate vehicle placement and stability control. Components such as steering knuckle are subjected to fatigue failures due to cyclic loads arising from various driving conditions. This paper intends to give a description of a method used in the fatigue life reliability evaluation of the knuckle used in a passenger car steering system. An accurate representation of Belgian pave service loads in terms of response-time history signal was obtained from accredited test track using road load data acquisition. The acquired service load data was replicated on durability test rig and the SN method was used to estimate the fatigue life. A Pearson system was developed to evaluate the predicted fatigue life reliability by considering the variations in material properties. Considering random loads experiences by the steering knuckle, it is found that shortest life appears to be in the vertical load direction with the lowest fatigue life reliability between 14000–16000 cycles. Taking into account the inconsistency of the material properties, the proposed method is capable of providing the probability of failure of mass-produced parts. E. A. Azrulhisham, Y. M. Asri, A. W. Dzuraidah, N. M. Nik Abdullah, A. Shahrum, and C. H. Che Hassan Copyright © 2010 E. A. Azrulhisham et al. All rights reserved. Mon, 20 Sep 2010 10:54:51 +0000 http://www.hindawi.com/journals/ijqsr/2010/180293/ The objective of this paper is to quantify the effect of autocorrelation coefficients, shift magnitude, types of control charts, types of controllers, and types of monitored signals on a control system. Statistical process control (SPC) and automatic process control (APC) were studied under non-stationary stochastic disturbances characterized by the integrated moving average model, ARIMA  (0,1,1). A process model was simulated to achieve two responses, mean squared error (MSE) and average run length (ARL). A factorial design experiment was conducted to analyze the simulated results. The results revealed that not only shift magnitude and the level of autocorrelation coefficients, but also the interaction between these two factors, affected the integrated system performance. It was also found that the most appropriate combination of SPC and APC is the utilization of the minimum mean squared error (MMSE) controller with the Shewhart moving range (MR) chart, while monitoring the control signal (X) from the controller. Therefore, integrating SPC and APC can improve process manufacturing, but the performance of the integrated system is significantly affected by process autocorrelation. Therefore, if the performance of the integrated system under non-stationary disturbances is correctly characterized, practitioners will have guidelines for achieving the highest possible performance potential when integrating SPC and APC. Karin Kandananond Copyright © 2010 Karin Kandananond. All rights reserved.