共查询到20条相似文献，搜索用时 46 毫秒
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多年来,广东科龙集团在企业内部大力推行IS09000质量管理的同时,也在不断完善和建立计量检测体系,贯彻执行ho100121标准c随着企业规模的不断扩大,科龙集团每年都要投入几千万元的资金,用于技术改造和技术引进项目,以及配备一些测量设备。测量设备管理已成为公司计量检测体系的重要组成部分。现在,全集团有近三万台（套）测量设备,由于许多测量设备属于进口设备,所以测量设备的策划管理尤为重要。1．划分职能,明确分工首先,根据GB／T19022－IS0100121标准中“测量设备策划”要素的要求,对测量设备策划进行计量职能分配,明确… 相似文献
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开展测量设备的周期检定,对于拥有测量设备类繁杂,数量庞大,专业性强的企事业单位来说,问题比较复杂,必须根据实际情况,建立科学的管理制度,建立合理的测量标准,编制适用的周检计划,对测量设备进行全面的管理,确保量值的准确一致,本结合我所的实际情况,对做好测量设备的周期检定谈一些粗浅的体会。 相似文献
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基于隐蔽的系统成败型数据的元件可靠性的极大似然估计和区间估计 总被引：4，自引：1，他引：3
考虑由３个独立工作的成败型元件组成的串联系统,利用隐蔽的系统寿命试验数据求元件可靠性的极大似然估计和区间估计,给出了数值例子。 相似文献
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计量检测设备校准周期的确定──学习ＩＳＯ１００１２体会之二航空航天工业部杨长禄，杨国恩ＩＳＯ１００１２－１是ＩＳＯ９０００系列标准的支撑性标准，是广大计量工作者贯彻ＩＳＯ９０００系列标准，使工业计量技术与管理与国际标准和惯例接轨的必修文件。ＩＳＯ１０... 相似文献
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企业计量检测设备的管理 总被引：1，自引：0，他引：1
青铜峡铝厂是一个拥有职工５９８３人 ,年产铝锭１０ ２万吨的大型企业。计量控制处统管全厂计量工作，现有职工１２６人。１９８９年获得国家一级计量单位合格证书 ;１９９６年通过国家级“完善计量检测体系”评审 ,获《完善计量检测体系合格证书》 ;２０００年１１月通过了ＩＳＯ９０００质量认证工作。一、企业计量检测设备的配置及作用每一个企业根据生产工艺、质量管理、经营管理、能源管理、物料管理需要配备一定数量的计量检测设备。其目的是用这些计量检测设备获得控制工艺、保证产品质量、提供经济核算所需要的科学数据。近年来 ,… 相似文献
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正企业测量管理体系的关键是测量过程控制的有效性,该有效性主要体现在维持测量结果的可信度。为了确保测量结果的可信度,必须使测量设备处于满足企业测量过程规定的要求。通常情况下,测量设备的计量性能(主要指最大允许误差)应不大于被测量允许测量值(或公差范围)的1/3。为了确定使用中的计量仪器满足上述要求,就需要按规定的程序对测量设 相似文献
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Mayank Kumar Jha Sanku Dey Refah Mohammed Alotaibi Yogesh Mani Tripathi 《Quality and Reliability Engineering International》2020,36(3):965-987
We consider the problem of estimating multicomponent stress-strength (MSS) reliability under progressive Type II censoring when stress and strength variables follow unit Gompertz distributions with common scale parameter. We estimate MSS reliability under frequentist and Bayesian approaches. Bayes estimates are obtained by using Lindley approximation and Metropolis-Hastings algorithm methods. Further, we obtain uniformly minimum variance unbiased estimates of the reliability when common scale parameter is known. Asymptotic, bootstrap confidence interval and highest posterior density credible intervals have been constructed. We perform Monte Carlo simulations to compare the performance of proposed estimates and also present a discussion. Finally, three real data sets are analyzed for illustrative purposes. 相似文献
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Maintenance management has a direct influence on equipment reliability and safety. However, a large portion of traditional maintenance models and reliability analysis methods usually assumes that only perfect maintenance is performed on the system and the system will restore to as good as new regardless of the kind of preventive maintenance work‐order that is performed. This is not practical in reality and may result in an inaccurate parametric estimation. The research objective of this paper is to develop a maximum likelihood estimation method to obtain more accurately estimated parameters based on the operational data of manufacturing systems, taking into consideration the difference between perfect and imperfect maintenance work‐orders. Weibull distribution is specifically studied for this purpose. A practical case study based on industrial operational data from an automotive assembly line is performed to illustrate the implementation and efficiency of the proposed reliability estimation method. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Young H. Chun 《国际生产研究杂志》2016,54(19):5686-5696
A complex product is often inspected more than once in a sequential manner to ensure the product’s quality. Based on the number of defects discovered during each round of inspection process, we can estimate the number of defects still remaining in the product. For each defect, the probability that the defect will be detected during each inspection cycle is usually assumed to be a known ‘constant’. However, in many practical situations, some defects are easily detected, while others are much more difficult to identify. In this paper, we propose a ‘beta-geometric’ inspection model in which the heterogeneity in detection probability is described by a beta distribution. In a numerical study, we show that our more realistic inspection model clearly outperforms traditional estimation methods that are based on the assumption of a constant detection probability. 相似文献
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New products are sometimes screened in the factory before shipment to the field. We show how to use failure time data from one of these screens to predict early field reliability. These reliability predictions are more economical and timely than reliability estimates that wait for data from field tracking studies. Further, these predictions are continuously responsive to the changes in reliability that frequently occur during the manufacture of a new product, and therefore, can form the basis of a rapid-feedback system for manufacturing process control. 相似文献
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《Quality Engineering》2012,24(3):359-369
ABSTRACT Reliability experiments provide important information regarding the life of a product, including how various factors affect product life. Current analyses of reliability data usually assume a completely randomized design. However, reliability experiments frequently contain subsampling, which represents a restriction on randomization. A typical experiment involves applying treatments to test stands, with several items placed on each test stand. In addition, raw materials used in experiments are often produced in batches, leading to a design involving blocks. This article proposes a method using Weibull regression for analyzing reliability experiments with random blocks and subsampling. An illustration of the method is provided. 相似文献
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根据振动理论,分析了直管式科氏质量流量计的最佳理论测量点;由于实际工程中必须考虑噪声条件,而在噪声环境中通常采用信号的最大似然估计算法,所以本文仿真了不同信噪比条件下的信号检测,结果表明最佳测量点同环境的噪声有关,并给出了不同信噪比条件下直管式科氏质量流量计最佳测量点。该结果同实验数据基本吻合。 相似文献
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《Quality Engineering》2012,24(4):392-400
ABSTRACT There are many real-life situations where exact failure times are not available or not easily available for reliability analysis. Motivated by this problem, this work is concerned with the analysis of reliability data without exact failure times. The unavailability of exact failure times has compelled us to develop a simplified version of the maximum likelihood (ML) estimation for reliability parameters and measures. The approach is applicable to single-parameter reliability models including the exponential reliability model and the Weibull reliability model with an assumed or known shape parameter value. In the latter case, it takes advantage of the fact that in many practical situations a reasonable estimate of the Weibull shape parameter is attainable by certain means. This is particularly valuable for reliability assessment of highly censored Weibull data with only a few failures, because in such situations it is highly desirable or necessary to exploit prior knowledge of the Weibull shape parameter to compensate for the limited information contained in the data in the hope of making a sound assessment. This is an application in a sense of the ideas and principles of the emerging paradigm of statistical engineering. The methods are developed by practitioners and for practitioners. We show that they offer practitioners a handy and efficient tool for reliability analysis, using hard disk drive product testing as examples. 相似文献
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F. K. Wang 《Quality and Reliability Engineering International》2001,17(4):257-267
The problem of constructing a confidence interval for the mean of non‐normal data is considered. The Bootstrap method and the Box–Cox transformation method of constructing the confidence interval are compared with the normal theory method. Simulation studies are used to evaluate the performance of these different methods of constructing confidence intervals. The result is not surprising; the Bootstrap method is more effective and efficient than the Box–Cox transformation method and the normal theory method in this simulation study. A real example demonstrates the ability of these methods to construct a confidence interval for the mean of audit accounting data. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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《Quality Engineering》2012,24(4):545-552
AbstractThe Weibull distribution has long been a popular choice for modeling lifetime data of various mechanical and biological phenomena when the associated hazard rate function is constant or monotone increasing or decreasing. However, nonmonotone hazard functions are common in reliability and survivability contexts where a system may undergo an initial “burn-in” prior to periods of useful life and eventual wear out. In these scenarios, the Weibull can only model a portion of the “bathtub” curve but is incapable of adequately modeling the entire failure process. Several modifications to the standard two-parameter Weibull distribution have therefore been introduced in the literature to effectively model and analyze lifetime data where the hazard rate function is bathtub-shaped. The performance of each modified distribution is typically assessed by its ability to fit a reference data set that is known to have a bathtub-shaped hazard rate function. The current article compares the performance of two recent contributions in this area to that of the poly-Weibull distribution with respect to several goodness-of-fit measures. In addition, numerical and analytical procedures are developed for obtaining the maximum likelihood parameter estimates, standard errors, and an equation to determine the moments for the generalized poly-Weibull distribution with arbitrary number of terms. Our results show that both the bi-Weibull and tri-Weibull distributions fit the reference data set better than the current best-fit models. 相似文献