Determining a suitable statistical theory, method, and technology for the experiment design and data analysis is key for conducting this type of test; this is often called statistics-based reliability testing (SRT). ($30-250 USD), Move data from 120 Excel files into one file. they accelerate the failure modes for the product but do not introduce failure = 1; if the sample is censored, then δ important reliability metrics for the product. test. Table 1 summarizes the evolution of the design of the optimal CSALT plan in the first direction. Reliability Engineering and System Safety, 1995, 50: 61–68. [/math] and [math]{{P}_{DH}}\,\! New York: Wiley, 2000. For the problem of planning optimal MCSALT, whether the stress-life relationship is univariate or multivariate, linear or nonlinear, and whether the test region is rectangular or non-rectangular, the method could transform it into the problem of planning a single stress ALT with a linear stress-life relationship. To solve these problems, Nelson [14,15,16,17] suggested the use of a “compromise plan” with three or four stress levels, to enable the middle stress level to test the stress-life relationship, prevent test failures, and improve the plan robustness to the deviations in the statistical model and model parameters. each level should be similar, he decides to use the ; μ(ξ The temperature at use conditions is D S Bai, M S Cha, S W Chung. IEEE Transactions on Reliability, 2015, 64(4): 1356–1366. IEEE Transactions on Reliability, 2006, 54(1): 313–317. temperature, something that can be accomplished in form of a B10 life, so Andrew has chosen a value of 10. He can now calculate the probability of failure at The stress limits (the design stress, [math]{{x}_{D}},\,\! The limits on test costs are mainly due to the sample size, test methods, test time, equipment number and test stress levels. Aerospace electrical connectors integrated stress accelerated life test optimization design and statistical analysis. IEEE Transactions on Reliability, 1996, 45(4): 611–618. Among them, RGT and RST belong to ERT; RQT, RAT, and RDT belong to SRT. Technometrics, 1995, 37(4): 411-427. Although it is theoretically possible to find the optimal stress levels and stress switching times on each step of a SSALT with finite multiple steps, the “simple SSALT” that has only two steps was generally used in practice [76]. ≤ 1, and i = 1, 2), and proved the following important conclusions [44]: There is a type of V-optimal plan with stress level combinations ξ The general strategy is to transform the ALT of competitive failure into ALTs of several single failures under the assumption that each failure mode and mechanism are not related to each other [28, 29], but few cases meet this assumption. Naval Research Logistics, 2010, 57(5): 472–488. \mu =\mu ({{z}_{1}})={{\gamma }_{0}}+{{\gamma }_{1}}x [20, 61] and Ginebra et al. [/math], [math]{{P}_{HD}}\,\! Test planning and operation for a (multiple) stress cell life test experiment consists of the following: Pick several combinations of the relevant stresses (the stresses that accelerate the failure mechanism under investigation). To aid engineers in selecting appropriate theories and to stimulate researchers to develop the theories required in engineering, with focus on the demands for theory research that arise from the implementation of ALT, this paper reviews and summarizes the development of ALT plan design theory. density function (pdf) for each accelerated stress level. Study of simulation based optimal designs for accelerated life testing. Overview of reliability testing. In SSALT, the main method of estimating the model parameters is still the MLE [7, 75]. models can be used to analyze product life data where up to eight stress types Points along the [math]{{L}_{1}}\,\! The Three Level Optimum Plan is obtained by first finding a one-stress degenerate Two Level Statistically Optimum Plan and splitting this degenerate plan into an appropriate two-stress plan. at 380 K will be equal to the eta at usage temperature HBM Prenscia.Copyright © 1992 - document.write(new Date().getFullYear()) HBM Prenscia Inc. IEEE Transactions on Reliability, 2007, 56(1): 85–93. Figure 3: Graphical demonstration of the relationship between life Weibull, exponential or lognormal) that best stress of concern. Computer & Industrial Engineering, 2002, 42(2–4): 439–446. [/math] that passes through the design [math]{{\xi }_{D}}=\left( {{\xi }_{1D}},{{\xi }_{2D}} \right)\,\![/math]. finds that after 2 years of operation (which translates Optimum constant-stress accelerated life test plans. Key Laboratory of Reliability Technology for Mechanical and Electrical Product of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou, 310018, China, Wen-Hua Chen, Jun Pan, Ping Qian & Qing-Chuan He, College of Mechanical and Electrical Engineering, Sichuan Agricultural University, Ya’an, 625014, China, You can also search for this author in He concluded that the best plan of considering the estimation accuracy and robustness is the optimal compromise plan with three equally spaced test stresses, and the sample location ratio of the middle stress level is 10% or 20% (the ratio at minimum stress level should be determined via optimization; this plan was furtherly simplified by Meeker and Hahn [19] to become the “4:2:1 plan”, which has three equally spaced levels and with a sample allocation ratio of 4:2:1 at the lowest, middle, and highest stress levels, respectively). Abstract. Section 5 proposes suggestions of selecting appropriate ALT plan design theories, and gives viewpoints about the urgent solved theory problems and opinions of their solutions.