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software reliability predictions
578
World Abstracts on Microelectronics and Reliability
system reliability and availability equations are developed. In addition, steady-state availability and mean-timebetween-failures expressions are developed. The special case when n = 2 is discussed numerically.
Software reliability analysis based on a nonhomogeneous error detection rate model SmGERU YAMADA,HIROYUKI NARIHISA and HmosHl OHTERA. Microelectron. Reliab. 24 (5) 915 (1984). A software reliability growth model discussed here assumes a nonhomogeneous error detection rate per error which characterizes a software reliability growth process during the testing phase. The methods for software reliability assessment are reviewed, and the model fitting and software reliability analysis for some software error data sets are presented. The optimum software release times are also given for the data analysis results. Combined hurdware/softwure reliability predictions. EUGENE FIO~NTINO and EDWARD C. SOISTMAN. Proc. a. Reliab. Maintainab. Syrup. 169 (1985). System reliability characterization and prediction techniques, which incorporate the combined effects of both hardware and software components and which reflect frequency of total system failures during mission or operating time, are needed by Air Force Systems planners and project officers. Unfortunately, techniques of this type do not exist at this time. This paper summarizes the activities and results of a study performed by Martin Marietta for the Rome Air Development Center. The purpose of the study was to develop characterization techniques for predicting total system reliability and to develop a methodology which can be used by system reliability engineers early in the design/development stages to evaluate various design approaches and alternatives against system quantitative reliability requirements. Since hardware reliability techniques have been well developed, the study concentrated primarily on the prediction of system software reliability which is defined herein as follows: System Software Reliability--The probability that the required software will perform its intended functions for the prescribed missions and time periods in the specified operating environment, without causing system outages or failures. The approach taken during this effort involved the performance of several interrelated subtasks including a literature search, a two-pass survey, and the development of the system prediction methodology.
programming, nonlinear integer programming, and nonlinear mixed integer programming problems. The algorithm contains a new technique for generating a succession of vector values of surrogate multiplier (i.e. surrogate problems). By using this technique, a computer can keep a polyhedron, which is a vector space of surrogatc multipliers to be considered at a certain time, in its memory. Furthermore it can cut the polyhedron by a given hyperplane, and produce the remaining space as the next polyhedron. Simple examples are included.
SYSREL: reliability of complex redundant systems. J. T. LAPOINTE and A. M. FORRY. Proc. a. Reliab. Maintainab. Syrup. 63 (1985). Determining the Mean-Time-BetweenFailure (MTBF) for highly redundant systems is an extremely tedious, if not mathematically difficult process. These systems are typically characterized by hierarchical application of nonidentical component (k of n) reliability calculations. Multiple levels in the hierarchy and large values of k and n make this calculation nearly intractable. A computer-aided technique to solve this class of problems is investigated. A deterministic combinatorial approach for predicting the reliability of complex redundant systems is presented. The approach avoids the need for sophisticated Markovian or Monte Carlo techniques and permits rapid evaluation of design and maintenance alternatives with minimal project resources. The overall approach involves modeling the system hierarchy and redundancy information by an indexing scheme based on reliability block diagrams. This scheme has proved to be simple and intuitive. Component reliabilities based on component failure rates and the exponential distribution are aggregated into nonidentical (k of n) group reliabilities by resource-conserving matrix techniques. Group calculations are performed recursively until the total system reliability has been determined. System and group MTBFs are calculated by efficient numerical integration techniques. A technique for adjusting system reliability to account for operational and maintenance profiles which restores lost redundancy is presented. A prototype program called SYSREL has been developed and tested for a VAX 11/780. A sample system is evaluated using SYSREL. The hypothetical sample case was specifically designed to illustrate the analytical difficulty in tackling many complex redundant systems. SYSREL results are presented for several design modifications and maintenance policies.
Computer aided stress analysis of digital circuits. MICHAELW. BANNAN and JAMES M. BANGHART. Proc. a. Reliab. Maintainab. Syrup. 217 (1985). A computer aid to the performance of a digital circuit stress analysis has been developed and is designed such that a clerk may input circuit interconnection data directly from a schematic with little or no involvement on the part of an engineer. The computer Application of the approximate solution of Poisson's equation performs the analysis at a significantly reduced cost and in a to derive new formulae for impurity profile determination by much shorter time than is possible with a manual analysis. In the C-V method. ANDRZ~ OSTROWSrd. Electron Technol. 15 addition to the increased accuracy and improved visibility, (3/4) 57 (1982). In this publication the formulae are derived the computer assistance allows the engineer time to pursue which are helpful in obtaining the real plots of impurity other equally beneficial tasks which may prove more profiles in semiconductors by means of the C - V method. challenging. They were obtained from the approximate solution of the Presented is a discussion of the events leading to the Poisson's equation. In this approximation the influence of determination of the need for this computer aid and the the free carriers (electrons and holes) can be also taken into theory of operation of the program itself. An illustrative account, it gives more exact results in comparison with example of a sample input and analysis is included. conventional Schottky approximation. Additionally, the many benefits realized, with virtually no added cost, are summarized. It is shown that these benefits Surrogate constraints algorithm for reliability optimization fall both within and outside the realm of stress analysis and problems with multiple constraints. YUJI NAKAGAWA, the reliability engineering discipline in general, and MITSUNORI HIKITA and Hmosm KAblADA. IEEE Trans. illustrates how they can be put to use to further support Reliab. R-33 (4) 301 (October 1984). This paper presents a design efforts. An actual cost and time savings summary is surrogate constraints algorithm for solving nonlinear also provided. On Murkov maintenance problems. YUKIO HATOYAMA.IEEE Trans. Reliab. R-33 (4) 280 (October 1984). The applicability of Markov maintenance models is crucial. We need to fill the gap between theoretical and practical maintenance problems. A model is proposed for that purpose.
World Abstracts on Microelectronics and Reliability
system reliability and availability equations are developed. In addition, steady-state availability and mean-timebetween-failures expressions are developed. The special case when n = 2 is discussed numerically.
Software reliability analysis based on a nonhomogeneous error detection rate model SmGERU YAMADA,HIROYUKI NARIHISA and HmosHl OHTERA. Microelectron. Reliab. 24 (5) 915 (1984). A software reliability growth model discussed here assumes a nonhomogeneous error detection rate per error which characterizes a software reliability growth process during the testing phase. The methods for software reliability assessment are reviewed, and the model fitting and software reliability analysis for some software error data sets are presented. The optimum software release times are also given for the data analysis results. Combined hurdware/softwure reliability predictions. EUGENE FIO~NTINO and EDWARD C. SOISTMAN. Proc. a. Reliab. Maintainab. Syrup. 169 (1985). System reliability characterization and prediction techniques, which incorporate the combined effects of both hardware and software components and which reflect frequency of total system failures during mission or operating time, are needed by Air Force Systems planners and project officers. Unfortunately, techniques of this type do not exist at this time. This paper summarizes the activities and results of a study performed by Martin Marietta for the Rome Air Development Center. The purpose of the study was to develop characterization techniques for predicting total system reliability and to develop a methodology which can be used by system reliability engineers early in the design/development stages to evaluate various design approaches and alternatives against system quantitative reliability requirements. Since hardware reliability techniques have been well developed, the study concentrated primarily on the prediction of system software reliability which is defined herein as follows: System Software Reliability--The probability that the required software will perform its intended functions for the prescribed missions and time periods in the specified operating environment, without causing system outages or failures. The approach taken during this effort involved the performance of several interrelated subtasks including a literature search, a two-pass survey, and the development of the system prediction methodology.
programming, nonlinear integer programming, and nonlinear mixed integer programming problems. The algorithm contains a new technique for generating a succession of vector values of surrogate multiplier (i.e. surrogate problems). By using this technique, a computer can keep a polyhedron, which is a vector space of surrogatc multipliers to be considered at a certain time, in its memory. Furthermore it can cut the polyhedron by a given hyperplane, and produce the remaining space as the next polyhedron. Simple examples are included.
SYSREL: reliability of complex redundant systems. J. T. LAPOINTE and A. M. FORRY. Proc. a. Reliab. Maintainab. Syrup. 63 (1985). Determining the Mean-Time-BetweenFailure (MTBF) for highly redundant systems is an extremely tedious, if not mathematically difficult process. These systems are typically characterized by hierarchical application of nonidentical component (k of n) reliability calculations. Multiple levels in the hierarchy and large values of k and n make this calculation nearly intractable. A computer-aided technique to solve this class of problems is investigated. A deterministic combinatorial approach for predicting the reliability of complex redundant systems is presented. The approach avoids the need for sophisticated Markovian or Monte Carlo techniques and permits rapid evaluation of design and maintenance alternatives with minimal project resources. The overall approach involves modeling the system hierarchy and redundancy information by an indexing scheme based on reliability block diagrams. This scheme has proved to be simple and intuitive. Component reliabilities based on component failure rates and the exponential distribution are aggregated into nonidentical (k of n) group reliabilities by resource-conserving matrix techniques. Group calculations are performed recursively until the total system reliability has been determined. System and group MTBFs are calculated by efficient numerical integration techniques. A technique for adjusting system reliability to account for operational and maintenance profiles which restores lost redundancy is presented. A prototype program called SYSREL has been developed and tested for a VAX 11/780. A sample system is evaluated using SYSREL. The hypothetical sample case was specifically designed to illustrate the analytical difficulty in tackling many complex redundant systems. SYSREL results are presented for several design modifications and maintenance policies.
Computer aided stress analysis of digital circuits. MICHAELW. BANNAN and JAMES M. BANGHART. Proc. a. Reliab. Maintainab. Syrup. 217 (1985). A computer aid to the performance of a digital circuit stress analysis has been developed and is designed such that a clerk may input circuit interconnection data directly from a schematic with little or no involvement on the part of an engineer. The computer Application of the approximate solution of Poisson's equation performs the analysis at a significantly reduced cost and in a to derive new formulae for impurity profile determination by much shorter time than is possible with a manual analysis. In the C-V method. ANDRZ~ OSTROWSrd. Electron Technol. 15 addition to the increased accuracy and improved visibility, (3/4) 57 (1982). In this publication the formulae are derived the computer assistance allows the engineer time to pursue which are helpful in obtaining the real plots of impurity other equally beneficial tasks which may prove more profiles in semiconductors by means of the C - V method. challenging. They were obtained from the approximate solution of the Presented is a discussion of the events leading to the Poisson's equation. In this approximation the influence of determination of the need for this computer aid and the the free carriers (electrons and holes) can be also taken into theory of operation of the program itself. An illustrative account, it gives more exact results in comparison with example of a sample input and analysis is included. conventional Schottky approximation. Additionally, the many benefits realized, with virtually no added cost, are summarized. It is shown that these benefits Surrogate constraints algorithm for reliability optimization fall both within and outside the realm of stress analysis and problems with multiple constraints. YUJI NAKAGAWA, the reliability engineering discipline in general, and MITSUNORI HIKITA and Hmosm KAblADA. IEEE Trans. illustrates how they can be put to use to further support Reliab. R-33 (4) 301 (October 1984). This paper presents a design efforts. An actual cost and time savings summary is surrogate constraints algorithm for solving nonlinear also provided. On Murkov maintenance problems. YUKIO HATOYAMA.IEEE Trans. Reliab. R-33 (4) 280 (October 1984). The applicability of Markov maintenance models is crucial. We need to fill the gap between theoretical and practical maintenance problems. A model is proposed for that purpose.