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large systems—a review
396
World Abstracts on Microelectronics and Reliability
reliability is evaluated, and some of the methods employed to increase it.
hazard rates. Two parameter-estimating procedures arc presented.
Burn-in: a new emphasis. PIETER S. BURGGRAAF. Semiconductor Int., 41 (May 1982). While many semiconductor manufacturers have been doing burn-in on ICs for the military, aerospace and other selected areas, they are now reexamining the capabilities of burn-in and finding it necessary for other circuits including all LSI and VLSI. Some users are content with static or dynamic burn-in, but others see tremendous benefits in monitored burn-in, and combinations of burn-in and functional test. These benefits include more productive test time, more reliable products and a better company reputation.
General formulas for calculating the steady-state frequency of system failure. DING-HUA SHI. IEEE Trans. Reliah. R-30 (5), 444 (198l). This paper develops two general formulas for directly converting the expression for steady-state availability or unavailability into frequency of system failure. Using the AggarwaI-Misra-Gupta fast algorithm, formulas for calculating the availability and failure-frequency of a ~-coherent system are derived.
Practical reliability methods for 11 kV and LV distribution systems. A. G. FISHER. Electronics Power, 504 (July/August 1982). Modern computing methods are helping distributionsystem-design engineers to better assess the reliability implications of network designs. This article explains some of the methods used, and the practical difficulties of applying reliability theory. Reliability simulation of hierarchic structures--comparison of the results of two different state models. H. B. BEMMANNand R. SPANNAUS. Nachrichtentechnik Elektronik 32 (H6), 254 (1982) (in German). The reliability data of hierarchic structure were calculated by simulation. As basis were used for one thing the stochastic model with a finite number of states and for another thing a model on the basis of state graphs. The efficiency of the two models is compared in tabular form. The question of the failure lapping in hierarchic structures is discussed. Discussion of "optimization by Integer programming of constrained reliability problems with several modes of failure". YUJI NAKAGAWAand YOSHIO HATTORI. IEEE Trans. Reliab. R-30 (5), 424 (1981). Tillman's 1969 treatment for components with several modes of failure and series (or parallel) redundancy using the components is discussed. This note claims that his treatment is wrong. Author replies and further discussion are provided. Failure analysis in brief. JIM EACHUS. Semiconductor Int., 103 (January 1982). This report serves as a s u m m a r y of basic failure rate, activation energy and median life calculation techniques. While computational aids are used, emphasis is placed on understanding the equations and theory behind the calculations. RESIN, a desktop-computer program for finding cut-sets. D. MAGEE and A. REFSUM. IEEE Trans. Reliab. R-30 (5), 407 (1981 ). This paper describes an efficient algorithm for finding the minimal cut-sets for the output nodes of any network. The advantages over previously published algorithms are that it can be used on a desktop computer, and it requires simpler input data preparation hence providing for rapid testing of the effect of network changes. System-reliability evaluation techniques for complex/large systems--a review. C. L. HWANG, FRANK A. T1LLMAN and M. H. LEE. IEEE Trans. Reliab. R-30 (5), 416 (1981). This paper is a review of literature related to system reliability evaluation techniques for small to large complex systems. The literature is classified according to system models and evaluation techniques. The technique(s) we recommend for each system model are indicated. Life distributions. BALBIR S. DHILLON. IEEE Trans. Reliab. R-30 (5), 457 (198l). This paper presents expressions for two distributions. The first distribution can represent increasing, decreasing, and bathtub hazard rates whereas the second distribution can only represent increasing and decreasing
R & M design--problem definition. ANTONIN WILD. IEEE Proc. Reliab., 309 (1982). Many deficiencies in R & M design are caused by a lack of proper definition of the problems to be solved. This paper indicates that the reason why problems are not properly defined can often be traced to a lack of communication between specialists involved in design. It shows how easily accessible computer tools for fault tree handling and M T B F prediction can help in defining the problems and are more effective for this task than for numerical assessments for which their use is better known.
Reliability growth, screened vs nonscreened computers. Et)wp, W. DERENTHAL. IEEE Proc. Reliab., 74 (1982). This paper (A) addresses the reliability improvement factor identified when digital computers subjected to a specific set of environmental screens were compared to virtually identical computers shipped without the screens, (B) answers the question of whether this improvement factor is constant throughout the life of the equipment, and (C) discusses the effect on reliability of extensive hardware modification made on hardware that had initially experienced signiticant reliability growth. Aerospace mechanical reliability practise. OTTO H. VEDOR. IEEE Proc. Reliab, 56 (1982). The impact of mechanical reliability practise on the Saturn/Apollo launch program is discussed with emphasis on the interrelationship of analysts and designers with management. The utility of ground testing and use of conservative design philosoph~ contributed to achieved reliability. Achieving maintainability by random fault injection. MtGU~L A. RAMIREZ. IEEE Proc. Reliab., 291 (1982). This paper describes a random fault injection testing technique that, when implemented, will significantly improve the probability of meeting maintainability requirements in the field. All too often, maintainability requirements are not met in the field because of inadequate validation and verification that can be traced directly to the lack of a testability growth program and the structured approach to qualification testing. The proposed random fault injection technique provides a testability growth program that concentrates on fault detection/isolation effectiveness and Mean-Time-To-Repair (MTTR). Examples of random fault injection data h)r Builtln-Test (BIT) and diagnostic software are provided to show the development/improvement of BIT capability and the maturation of diagnostic software. Identification of factors which cause software failure. Gt~og¢iE RZEVSKI. IEEE Proc. Reliab., 157 (1982). The paper describes some results of extensive research into the causes of software reliability and methods for software reliability improvement. A large number of factors which affect the occurrence of h u m a n errors during software development and maintenance have been identified. Since a considerable number of these factors are related to characteristics of software projects, one of the conclusions of the paper is that, in order to achieve software reliability through fault avoidance, there is a need for a systematic and comprehensive project management methodology which would provide means of controlling these factors.
World Abstracts on Microelectronics and Reliability
reliability is evaluated, and some of the methods employed to increase it.
hazard rates. Two parameter-estimating procedures arc presented.
Burn-in: a new emphasis. PIETER S. BURGGRAAF. Semiconductor Int., 41 (May 1982). While many semiconductor manufacturers have been doing burn-in on ICs for the military, aerospace and other selected areas, they are now reexamining the capabilities of burn-in and finding it necessary for other circuits including all LSI and VLSI. Some users are content with static or dynamic burn-in, but others see tremendous benefits in monitored burn-in, and combinations of burn-in and functional test. These benefits include more productive test time, more reliable products and a better company reputation.
General formulas for calculating the steady-state frequency of system failure. DING-HUA SHI. IEEE Trans. Reliah. R-30 (5), 444 (198l). This paper develops two general formulas for directly converting the expression for steady-state availability or unavailability into frequency of system failure. Using the AggarwaI-Misra-Gupta fast algorithm, formulas for calculating the availability and failure-frequency of a ~-coherent system are derived.
Practical reliability methods for 11 kV and LV distribution systems. A. G. FISHER. Electronics Power, 504 (July/August 1982). Modern computing methods are helping distributionsystem-design engineers to better assess the reliability implications of network designs. This article explains some of the methods used, and the practical difficulties of applying reliability theory. Reliability simulation of hierarchic structures--comparison of the results of two different state models. H. B. BEMMANNand R. SPANNAUS. Nachrichtentechnik Elektronik 32 (H6), 254 (1982) (in German). The reliability data of hierarchic structure were calculated by simulation. As basis were used for one thing the stochastic model with a finite number of states and for another thing a model on the basis of state graphs. The efficiency of the two models is compared in tabular form. The question of the failure lapping in hierarchic structures is discussed. Discussion of "optimization by Integer programming of constrained reliability problems with several modes of failure". YUJI NAKAGAWAand YOSHIO HATTORI. IEEE Trans. Reliab. R-30 (5), 424 (1981). Tillman's 1969 treatment for components with several modes of failure and series (or parallel) redundancy using the components is discussed. This note claims that his treatment is wrong. Author replies and further discussion are provided. Failure analysis in brief. JIM EACHUS. Semiconductor Int., 103 (January 1982). This report serves as a s u m m a r y of basic failure rate, activation energy and median life calculation techniques. While computational aids are used, emphasis is placed on understanding the equations and theory behind the calculations. RESIN, a desktop-computer program for finding cut-sets. D. MAGEE and A. REFSUM. IEEE Trans. Reliab. R-30 (5), 407 (1981 ). This paper describes an efficient algorithm for finding the minimal cut-sets for the output nodes of any network. The advantages over previously published algorithms are that it can be used on a desktop computer, and it requires simpler input data preparation hence providing for rapid testing of the effect of network changes. System-reliability evaluation techniques for complex/large systems--a review. C. L. HWANG, FRANK A. T1LLMAN and M. H. LEE. IEEE Trans. Reliab. R-30 (5), 416 (1981). This paper is a review of literature related to system reliability evaluation techniques for small to large complex systems. The literature is classified according to system models and evaluation techniques. The technique(s) we recommend for each system model are indicated. Life distributions. BALBIR S. DHILLON. IEEE Trans. Reliab. R-30 (5), 457 (198l). This paper presents expressions for two distributions. The first distribution can represent increasing, decreasing, and bathtub hazard rates whereas the second distribution can only represent increasing and decreasing
R & M design--problem definition. ANTONIN WILD. IEEE Proc. Reliab., 309 (1982). Many deficiencies in R & M design are caused by a lack of proper definition of the problems to be solved. This paper indicates that the reason why problems are not properly defined can often be traced to a lack of communication between specialists involved in design. It shows how easily accessible computer tools for fault tree handling and M T B F prediction can help in defining the problems and are more effective for this task than for numerical assessments for which their use is better known.
Reliability growth, screened vs nonscreened computers. Et)wp, W. DERENTHAL. IEEE Proc. Reliab., 74 (1982). This paper (A) addresses the reliability improvement factor identified when digital computers subjected to a specific set of environmental screens were compared to virtually identical computers shipped without the screens, (B) answers the question of whether this improvement factor is constant throughout the life of the equipment, and (C) discusses the effect on reliability of extensive hardware modification made on hardware that had initially experienced signiticant reliability growth. Aerospace mechanical reliability practise. OTTO H. VEDOR. IEEE Proc. Reliab, 56 (1982). The impact of mechanical reliability practise on the Saturn/Apollo launch program is discussed with emphasis on the interrelationship of analysts and designers with management. The utility of ground testing and use of conservative design philosoph~ contributed to achieved reliability. Achieving maintainability by random fault injection. MtGU~L A. RAMIREZ. IEEE Proc. Reliab., 291 (1982). This paper describes a random fault injection testing technique that, when implemented, will significantly improve the probability of meeting maintainability requirements in the field. All too often, maintainability requirements are not met in the field because of inadequate validation and verification that can be traced directly to the lack of a testability growth program and the structured approach to qualification testing. The proposed random fault injection technique provides a testability growth program that concentrates on fault detection/isolation effectiveness and Mean-Time-To-Repair (MTTR). Examples of random fault injection data h)r Builtln-Test (BIT) and diagnostic software are provided to show the development/improvement of BIT capability and the maturation of diagnostic software. Identification of factors which cause software failure. Gt~og¢iE RZEVSKI. IEEE Proc. Reliab., 157 (1982). The paper describes some results of extensive research into the causes of software reliability and methods for software reliability improvement. A large number of factors which affect the occurrence of h u m a n errors during software development and maintenance have been identified. Since a considerable number of these factors are related to characteristics of software projects, one of the conclusions of the paper is that, in order to achieve software reliability through fault avoidance, there is a need for a systematic and comprehensive project management methodology which would provide means of controlling these factors.