[en] The methodology described here talks about some parts of the study concerning the failures of a determined system or supposed such. In these parts appears the most important logical and algebraic calculus. They are processed after the transformation of the system in the form of an equivalent functional scheme. The purpose of this methodology is the study of the effect of failure, of repairing or drift for one or several devices

[en] It is assumed that the phenomenon under study is such that the time-to-failure may be modeled by an exponential distribution with failure rate lambda. For Bayesian analyses of the assumed model, the family of gamma distributions provides conjugate prior models for lambda. Thus, an experimenter needs to select a particular gamma model to conduct a Bayesian reliability analysis. The purpose of this report is to present a methodology that can be used to translate engineering information, experience, and judgment into a choice of a gamma prior distribution. The proposed methodology assumes that the practicing engineer can provide percentile data relating to either the failure rate or the reliability of the phenomenon being investigated. For example, the methodology will select the gamma prior distribution which conveys an engineer's belief that the failure rate lambda simultaneously satisfies the probability statements, P(lambda less than 1.0 x 10^-3) equals 0.50 and P(lambda less than 1.0 x 10^-5) equals 0.05. That is, two percentiles provided by an engineer are used to determine a gamma prior model which agrees with the specified percentiles. For those engineers who prefer to specify reliability percentiles rather than the failure rate percentiles illustrated above, it is possible to use the induced negative-log gamma prior distribution which satisfies the probability statements, P(R(t₀) less than 0.99) equals 0.50 and P(R(t₀) less than 0.99999) equals 0.95, for some operating time t₀. The report also includes graphs for selected percentiles which assist an engineer in applying the procedure. 28 figures, 16 tables

[en] Application of reliability and risk analysis methods (particularly fault trees) to failure analysis of systems in hostile manmade environments is discussed. Methods for constructing, analyzing, and interpreting the fault trees, graphs, and diagrams are described. The application of fault-trees, directed graphs, and functional diagrams to problems in sabotage, survivability, and information protection is discussed in general terms. Special problems encountered in this type of analysis are discussed, and future research directions are considered

[en] The breakdown-combinations method is a method for analysing systems reliability and safety, initially developed in aeronautics. This method is presented in this paper and then applied, as an example, to a simple set of systems

[en] Experience has shown that reliability assessments can play an important role in the early design and subsequent operation of technological systems where reliability is at a premium. The approaches to and techniques for such assessments, which have been outlined in the paper, have been successfully applied in variety of applications ranging from individual equipments to large and complex systems. The general approach involves the logical and systematic establishment of the purpose, performance requirements and reliability criteria of systems. This is followed by an appraisal of likely system achievment based on the understanding of different types of variational behavior. A fundamental reliability model emerges from the correlation between the appropriate Q and H functions for performance requirement and achievement. This model may cover the complete spectrum of performance behavior in all the system dimensions

[en] Measures of differences in reliability of two systems are considered in the scale model, location-scale model, and a nonparametric model. In each model, estimates and confidence intervals are given and some of their properties discussed

[en] This paper describes a new method for analyzing data. The method applies to non-negative observations such as times to failure of devices and survival times of biological organisms and involves a plot of the data. These plots are useful in choosing a probabilistic model to represent the failure behavior of the data. They also furnish information about the failure rate function and aid in its estimation. An important feature of these data plots is that incomplete data can be analyzed. The underlying random variables are, however, assumed to be independent and identically distributed. The plots have a theoretical basis, and converge to a transform of the underlying probability distribution as the sample size increases

[en] Failure analysis is a critical element in the integrated circuit manufacturing industry. This paper reviews the changing role of failure analysis and describes major techniques employed in the industry today. Several advanced failure analysis techniques that meet the challenges imposed by advancements in integrated circuit technology are described and their applications are discussed. Future trends in failure analysis needed to keep pace with the continuing advancements in integrated circuit technology are anticipated

[en] The generalized likehood radio(GLR) method performs statistical tests on the innovations sequence of a Kalman-Buchy filter state estimator for system failure detection and its identification. However, the major drawback of the convensional GLR is to hypothesize particular failure type in each case. In this paper, a method to solve this drawback is proposed. The improved GLR method is applied to a PWR pressurizer and gives successful results in detection and identification of any failure. Furthmore, some benefit on the processing time per each cycle of failure detection and its identification can be accompanied. (Author)

[en] In the design of a new system, or the maintenance of an old system, allocation of resources is of prime consideration. In allocating resources it is often beneficial to develop a solution that yields an optimal value of the system measure of desirability. In the context of the problems considered in this paper the resources to be allocated are components already produced (assembly problems) and money (allocation in the construction or repair of systems). The measure of desirability for system assembly will usually be maximizing the expected number of systems that perform satisfactorily and the measure in the allocation context will be maximizing the system reliability. Results are presented for these two types of general problems in both a sequential (when appropriate) and non-sequential context