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A perspective on computer reliability
WORLD
ABSTRACTS
ON MICROELECTRONICS
AND
RELIABILITY
413
3. CIRCUIT AND SYSTEMS RELIABILITY, MAINTENANCE AND REDUNDANCY R e l i a b i l i t y m e a s u r e m e n t s for t h l r d - g e n e r a t l o n computer s y s t e m s . E. YOURDON. Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. IEEE Cat. No. 72CH0577-7R. 25-27 January (1972), p. 174. T h e purpose of this paper is to illustrate the cumulative effects of hardware and software upon system reliability by showing some statistics from a collection of third-generation computer systems. These statistics were gathered by the users of the computer systems, and as such are not as complete and accurate as would be desired; nevertheless, they are helpful if only to show how serious the problem is, and how much work remains to be done. A p e r s p e c t i v e on computer reliability. M. J. FLYNN and S. A. SZYGENDA.Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. IEEE Cat. No. 72CH0577-7R. 25-27 January (1972), p. 166. This paper attempts to establish a unified view of the field of computer reliability, including considerations for reliable design, redundancy techniques and diagnosis. T o reflect this, the paper is divided into three sections. In the first section, we will discuss a priori design which is indigenous to the decision element. T h a t is, the establishment of a suitable design criteria to minimize the incidence of faults. In the second section, we will be concerned with a posteriori failures or the exogenous manifestations of faults. I n particular, we will be coneerned with detecting and correcting such failures and hence masking their effect to the system. In the final section, we will be concerned with fault diagnosis of the defective system and isolation of failing modules for system maintenance.
The reHabili W engineer and the interactive terminal, K. A. LYMAN. Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. I E E E Cat. No. 72CH0577-7R. 25-27 January (1972), p. 44. Introduction of time-shared remote terminals interfacing with a large-scale computer has resulted in a quantum step of effectiveness in utilization of mancomputer interactive systems. From humble beginnings in the Johniac Open-Shop System and Project M A C at M I T , time-shared systems have grown to large networks of interlaced computers in operation today. T h e remote interactive terminal access has provided a capability for any scientist or engineer to acquire the facilities of battalions of clerks using desk calculators, to test the mathematical performance of his every whim. Statisticians and reliability engineers can particularly enjoy this facility from the point of view of ease of inputting data, control of book-keeping which applying and operating upon the data, and the abundance of variable formats. Reliability test of MOS/LSI-memory for the i m p r o v e m e n t of the fabrication t e c h n i q u e s . Y. TARui, Y. I-/AYASHI, N. NARUKAMI and K. ISHXi. Trans. Inst. Elect. Commun. Engrs. ffapan 55-C (1972), p. 114. (In Japanese.) This paper describes the reliability
aspect of checking and improvement of the fabrication technique from the stage of the pilto production to the mass production of n-channel M O S / L S I - m e m o r y developed for the national project of the high-speed computer. T h e main purpose of this paper is to report the results of this test, and then to describe the method and effect of the reliability tests by measuring the frequency of the ring oscillators constructed from the test specimens. T h e results were fed back to the final production, which was improved by three orders of magnitude in the M T T F . A p r a c t i c a l a n a l y s i s of the sedentary failure rate. S. M. CrmRKASKY. Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. I E E E Cat. No. 72CH0577-7R. 25-27 January (1972), p. 465. This paper treats the subject matter's effect on dormant aerospace systems in a three-phase approach. First, the concept of a non-operating or "sedentary" failure rate is presented; secondly, Singer-Kearfott Division's storage data is compared to existing published data; and finally, a practical prediction technique is offered, based on the interaction of part mixes and associated secondary factors. T h e sedentary or non-operating failure rate is that failure rate which prevails while equipment is just "sitting", in a dormant unenergized state. Conclusions and recommendations are offered and substantiated with supporting data, where possible. In addition, the current technology, as well as voids in this technology, will be examined along with several suggestions to the industry for diminishing some of the present indecision in this challenging area. Singer-KD storage data on militarystandard electronic piece parts indicate that other failure rate sources might tend to be pessimistic. Furthermore, there exists satisfactory correlation between predicted and observed non-operating failure rates using the prediction methodology offered herein. Although the problem of storage induced failures is gaining recognition, its impact has still not been fully appreciated. It is hoped that this paper will offer a more practical treatment of this current reliability challenge.
Failure modes, effects a n d c r i t i c a l i W a n a l y s e s . W. E. JORDAN. Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. IEEE Cat. No. 72CH0577-7R. 25-27 January (1972), p. 30. Failure mode, effects and criticality analyses were developed by NASA as a means of assuring that hardware built for space applications has the desired reliability characteristics. T h e failure mode and effects analysis is a qualitative reliability technique for systematically analyzing each possible failure mode within a hardware system, and identifying the resulting effect on that system, the mission and personnel. T h e criticality analysis is a quantitative procedure which ranks the critical failure modes according to their probability of occurrence. This paper describes the failure modes, effects analysis and the criticality analysis. I t employs a simple hardware system, not related to the aerospace field, to illustrate the method. It encourages application of this type of
ABSTRACTS
ON MICROELECTRONICS
AND
RELIABILITY
413
3. CIRCUIT AND SYSTEMS RELIABILITY, MAINTENANCE AND REDUNDANCY R e l i a b i l i t y m e a s u r e m e n t s for t h l r d - g e n e r a t l o n computer s y s t e m s . E. YOURDON. Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. IEEE Cat. No. 72CH0577-7R. 25-27 January (1972), p. 174. T h e purpose of this paper is to illustrate the cumulative effects of hardware and software upon system reliability by showing some statistics from a collection of third-generation computer systems. These statistics were gathered by the users of the computer systems, and as such are not as complete and accurate as would be desired; nevertheless, they are helpful if only to show how serious the problem is, and how much work remains to be done. A p e r s p e c t i v e on computer reliability. M. J. FLYNN and S. A. SZYGENDA.Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. IEEE Cat. No. 72CH0577-7R. 25-27 January (1972), p. 166. This paper attempts to establish a unified view of the field of computer reliability, including considerations for reliable design, redundancy techniques and diagnosis. T o reflect this, the paper is divided into three sections. In the first section, we will discuss a priori design which is indigenous to the decision element. T h a t is, the establishment of a suitable design criteria to minimize the incidence of faults. In the second section, we will be concerned with a posteriori failures or the exogenous manifestations of faults. I n particular, we will be coneerned with detecting and correcting such failures and hence masking their effect to the system. In the final section, we will be concerned with fault diagnosis of the defective system and isolation of failing modules for system maintenance.
The reHabili W engineer and the interactive terminal, K. A. LYMAN. Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. I E E E Cat. No. 72CH0577-7R. 25-27 January (1972), p. 44. Introduction of time-shared remote terminals interfacing with a large-scale computer has resulted in a quantum step of effectiveness in utilization of mancomputer interactive systems. From humble beginnings in the Johniac Open-Shop System and Project M A C at M I T , time-shared systems have grown to large networks of interlaced computers in operation today. T h e remote interactive terminal access has provided a capability for any scientist or engineer to acquire the facilities of battalions of clerks using desk calculators, to test the mathematical performance of his every whim. Statisticians and reliability engineers can particularly enjoy this facility from the point of view of ease of inputting data, control of book-keeping which applying and operating upon the data, and the abundance of variable formats. Reliability test of MOS/LSI-memory for the i m p r o v e m e n t of the fabrication t e c h n i q u e s . Y. TARui, Y. I-/AYASHI, N. NARUKAMI and K. ISHXi. Trans. Inst. Elect. Commun. Engrs. ffapan 55-C (1972), p. 114. (In Japanese.) This paper describes the reliability
aspect of checking and improvement of the fabrication technique from the stage of the pilto production to the mass production of n-channel M O S / L S I - m e m o r y developed for the national project of the high-speed computer. T h e main purpose of this paper is to report the results of this test, and then to describe the method and effect of the reliability tests by measuring the frequency of the ring oscillators constructed from the test specimens. T h e results were fed back to the final production, which was improved by three orders of magnitude in the M T T F . A p r a c t i c a l a n a l y s i s of the sedentary failure rate. S. M. CrmRKASKY. Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. I E E E Cat. No. 72CH0577-7R. 25-27 January (1972), p. 465. This paper treats the subject matter's effect on dormant aerospace systems in a three-phase approach. First, the concept of a non-operating or "sedentary" failure rate is presented; secondly, Singer-Kearfott Division's storage data is compared to existing published data; and finally, a practical prediction technique is offered, based on the interaction of part mixes and associated secondary factors. T h e sedentary or non-operating failure rate is that failure rate which prevails while equipment is just "sitting", in a dormant unenergized state. Conclusions and recommendations are offered and substantiated with supporting data, where possible. In addition, the current technology, as well as voids in this technology, will be examined along with several suggestions to the industry for diminishing some of the present indecision in this challenging area. Singer-KD storage data on militarystandard electronic piece parts indicate that other failure rate sources might tend to be pessimistic. Furthermore, there exists satisfactory correlation between predicted and observed non-operating failure rates using the prediction methodology offered herein. Although the problem of storage induced failures is gaining recognition, its impact has still not been fully appreciated. It is hoped that this paper will offer a more practical treatment of this current reliability challenge.
Failure modes, effects a n d c r i t i c a l i W a n a l y s e s . W. E. JORDAN. Proceedings 1972 Annual Reliability and Maintainability Symposium, San Francisco. IEEE Cat. No. 72CH0577-7R. 25-27 January (1972), p. 30. Failure mode, effects and criticality analyses were developed by NASA as a means of assuring that hardware built for space applications has the desired reliability characteristics. T h e failure mode and effects analysis is a qualitative reliability technique for systematically analyzing each possible failure mode within a hardware system, and identifying the resulting effect on that system, the mission and personnel. T h e criticality analysis is a quantitative procedure which ranks the critical failure modes according to their probability of occurrence. This paper describes the failure modes, effects analysis and the criticality analysis. I t employs a simple hardware system, not related to the aerospace field, to illustrate the method. It encourages application of this type of