Finite element analysis (FEA) was performed on three different surface mounted designs: a leadless chip carrier, gull-wing chip carrier, and compliant S-lead leadless chip carrier. The output of the FEA was input into the Coffin-Manson model, and the number of thermal cycles to failure was estimated. The results indicated that the gull-wing and S-leads chip carriers would be reliable when placed in this temperature environment but the leadless chip carriers would have reliability problems after a short period of time.<>
{"title":"Predicting time-to-failure using finite element analysis","authors":"G. A. Bivens","doi":"10.1109/ARMS.1990.67976","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67976","url":null,"abstract":"Finite element analysis (FEA) was performed on three different surface mounted designs: a leadless chip carrier, gull-wing chip carrier, and compliant S-lead leadless chip carrier. The output of the FEA was input into the Coffin-Manson model, and the number of thermal cycles to failure was estimated. The results indicated that the gull-wing and S-leads chip carriers would be reliable when placed in this temperature environment but the leadless chip carriers would have reliability problems after a short period of time.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129246412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A method for measuring the break rate (BR) of an individual avionics system is described. The method is convenient early in the design process and accounts for item criticality, redundancy, task deferrability, and when deferred tasks are repaired. Also introduced is a new criterion of effectiveness, sortie loss rate, as an alternative to BR. Sortie loss rate has the benefit of measuring the total number of potential military sorties missed due to unscheduled maintenance. BR is calculated as the number of sorties missed divided by the number of sorties attempted. An alternative way to compute BR is one minus the ratio of actual sorties launched to attempted sorties.<>
{"title":"Break rate: a reliability parameter for surge operations","authors":"J. K. Seger","doi":"10.1109/ARMS.1990.67991","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67991","url":null,"abstract":"A method for measuring the break rate (BR) of an individual avionics system is described. The method is convenient early in the design process and accounts for item criticality, redundancy, task deferrability, and when deferred tasks are repaired. Also introduced is a new criterion of effectiveness, sortie loss rate, as an alternative to BR. Sortie loss rate has the benefit of measuring the total number of potential military sorties missed due to unscheduled maintenance. BR is calculated as the number of sorties missed divided by the number of sorties attempted. An alternative way to compute BR is one minus the ratio of actual sorties launched to attempted sorties.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125685673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A procedure is described by which reliability and maintainability considerations can be taken into account when ranking options for the selection of built-in test (BIT) devices. The type of constraints that are likely to influence BIT selection usually fall into one of the following categories: money, space and weight, manpower, time, and computer power and memory. Quality measures-factors which influence the overall objectives sought when employing BIT-are increasing the availability and reliability of the system and decreasing the system's probability of a safety incident when the BIT is capable of detecting safety-critical failure modes.<>
{"title":"An approach to the selection of built-in-test devices","authors":"A. Rosin","doi":"10.1109/ARMS.1990.67981","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67981","url":null,"abstract":"A procedure is described by which reliability and maintainability considerations can be taken into account when ranking options for the selection of built-in test (BIT) devices. The type of constraints that are likely to influence BIT selection usually fall into one of the following categories: money, space and weight, manpower, time, and computer power and memory. Quality measures-factors which influence the overall objectives sought when employing BIT-are increasing the availability and reliability of the system and decreasing the system's probability of a safety incident when the BIT is capable of detecting safety-critical failure modes.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126142126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Criticality, as defined by K.K. Aggarwal (Proc. Ann. Reliability and Maintainability Symp., p.86-9, 1989), is shown to be an adaptation of conditional probability theory. Both of these methods are shown to be acceptable techniques for modeling a simple radio network. However, the equivalent parallel-configuration approach provided a much simpler way of modeling the radio network problem, by using standard techniques in a new way. The logical interpretation of not-fully-critical subunits is clearly modeled with a simple manipulation of the standard reliability block diagram. The equivalent parallel-configuration approach is shown to be useful in modeling any situation where failed components may or may not lead to system failure.<>
{"title":"Radio network modeling using criticality and conditional probability theory","authors":"P.A. Roman, B. Simms","doi":"10.1109/ARMS.1990.67946","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67946","url":null,"abstract":"Criticality, as defined by K.K. Aggarwal (Proc. Ann. Reliability and Maintainability Symp., p.86-9, 1989), is shown to be an adaptation of conditional probability theory. Both of these methods are shown to be acceptable techniques for modeling a simple radio network. However, the equivalent parallel-configuration approach provided a much simpler way of modeling the radio network problem, by using standard techniques in a new way. The logical interpretation of not-fully-critical subunits is clearly modeled with a simple manipulation of the standard reliability block diagram. The equivalent parallel-configuration approach is shown to be useful in modeling any situation where failed components may or may not lead to system failure.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126327864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The design of fault-tolerant systems to tolerate a larger number of faults without a significant increase in the amount of redundancy is discussed. The technique is to partition a module into submodules and provide local redundancy. The results are illustrated for a duplex system and then generalized to other fault-tolerant systems. The issue of optimal partitioning is also addressed.<>
{"title":"Reliability enhancement by submodule redundancy","authors":"S. Upadhyaya, H. Pham, K. Saluja","doi":"10.1109/ARMS.1990.67944","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67944","url":null,"abstract":"The design of fault-tolerant systems to tolerate a larger number of faults without a significant increase in the amount of redundancy is discussed. The technique is to partition a module into submodules and provide local redundancy. The results are illustrated for a duplex system and then generalized to other fault-tolerant systems. The issue of optimal partitioning is also addressed.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132986026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In developing new failure rate models in MIL-HDBK-217E for microcircuits, the need for updated values of three failure-rate adjustment factors (pi-factors) became evident. These pi-factors are the quality factor, the environmental factor, and the learning factor. The logic, methodology, and results of the approach taken in developing these factors are addressed, and a discussion on how to use each pi-factor is provided. The pi-factors discussed are different from those presented in past revisions of MIL-HDBK-217 in that they have been derived from different sets of data from those used to develop the microcircuit models. They are generic to all microcircuits, are flexible and easy to use, and relate to physical attributes (such as device screening) or applicable military specifications.<>
{"title":"Pi factors revisited","authors":"R. Seidl, W. Garry","doi":"10.1109/ARMS.1990.67924","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67924","url":null,"abstract":"In developing new failure rate models in MIL-HDBK-217E for microcircuits, the need for updated values of three failure-rate adjustment factors (pi-factors) became evident. These pi-factors are the quality factor, the environmental factor, and the learning factor. The logic, methodology, and results of the approach taken in developing these factors are addressed, and a discussion on how to use each pi-factor is provided. The pi-factors discussed are different from those presented in past revisions of MIL-HDBK-217 in that they have been derived from different sets of data from those used to develop the microcircuit models. They are generic to all microcircuits, are flexible and easy to use, and relate to physical attributes (such as device screening) or applicable military specifications.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130163818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The concept, implementation, and long-range goals of a supportability-trend analysis and reporting system (STARS) for the National Space Transportation System (NSTS) are discussed. The requirement was established as a direct result of the recommendations of the Rogers Commission investigation of the circumstances of the Space Shuttle Challenger accident. STARS outlines the requirements for the supportability-trend data collection, analysis, and reporting requirements that each of the project offices supporting the Space Shuttle are required to provide to the NSTS program office. STARS data give the historic and predictive logistics information necessary for all levels of NSTS management to make safe and cost-effective decisions concerning the smooth flow of Space Shuttle turnaround.<>
{"title":"STARS-supportability trend analysis and reporting system for the National Space Transportation System","authors":"L. J. Graham, G.T. Doempke","doi":"10.1109/ARMS.1990.67928","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67928","url":null,"abstract":"The concept, implementation, and long-range goals of a supportability-trend analysis and reporting system (STARS) for the National Space Transportation System (NSTS) are discussed. The requirement was established as a direct result of the recommendations of the Rogers Commission investigation of the circumstances of the Space Shuttle Challenger accident. STARS outlines the requirements for the supportability-trend data collection, analysis, and reporting requirements that each of the project offices supporting the Space Shuttle are required to provide to the NSTS program office. STARS data give the historic and predictive logistics information necessary for all levels of NSTS management to make safe and cost-effective decisions concerning the smooth flow of Space Shuttle turnaround.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127924300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Test data from burn-in of complex electromechanical systems were analyzed using hazard plots in order to determine whether the systems were being tested for the optimum length of time. The problems encountered were how to determine the failure distribution and its parameters for multiply censored data and how to put it in a form easily understood by those outside the reliability field. A BASIC computer code generated plots of multiply censored data, consisting of test results for nine systems, for five common distributions to determine the best fit. It was found that the effects of burn-in at the module level could best be seen as the system level using the three-parameter Weibull distribution. From a so-called bathtub curve plot showing the change in instantaneous failure rate as a function of run-in time (wafers), intuitive conclusions can be drawn regarding the adequacy of run-in. Alternatively, the asymptotic instantaneous failure rate can be used as the useful life failure rate in cost equations, which should provide an objective measure of the adequacy of run-in.<>
{"title":"Analysis of multiply censored run-in data","authors":"J. Elerath","doi":"10.1109/ARMS.1990.68009","DOIUrl":"https://doi.org/10.1109/ARMS.1990.68009","url":null,"abstract":"Test data from burn-in of complex electromechanical systems were analyzed using hazard plots in order to determine whether the systems were being tested for the optimum length of time. The problems encountered were how to determine the failure distribution and its parameters for multiply censored data and how to put it in a form easily understood by those outside the reliability field. A BASIC computer code generated plots of multiply censored data, consisting of test results for nine systems, for five common distributions to determine the best fit. It was found that the effects of burn-in at the module level could best be seen as the system level using the three-parameter Weibull distribution. From a so-called bathtub curve plot showing the change in instantaneous failure rate as a function of run-in time (wafers), intuitive conclusions can be drawn regarding the adequacy of run-in. Alternatively, the asymptotic instantaneous failure rate can be used as the useful life failure rate in cost equations, which should provide an objective measure of the adequacy of run-in.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124810717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work reviews possible hardware-redundancy techniques for long-haul fiberoptic communications systems designed to operate undersea. Approaches are analyzed from a complexity viewpoint, taking into account overall system supervisory techniques, fiber-routing considerations and repair strategies and reducing the options to a short list of four on this basis. These four options are compared via a detailed reliability analysis employing the matrix method, a recently developed algorithm based on Markov theory.<>
{"title":"Long-haul undersea communications systems: hardware redundancy techniques for ultra-reliability","authors":"R. Murphy","doi":"10.1109/ARMS.1990.67952","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67952","url":null,"abstract":"This work reviews possible hardware-redundancy techniques for long-haul fiberoptic communications systems designed to operate undersea. Approaches are analyzed from a complexity viewpoint, taking into account overall system supervisory techniques, fiber-routing considerations and repair strategies and reducing the options to a short list of four on this basis. These four options are compared via a detailed reliability analysis employing the matrix method, a recently developed algorithm based on Markov theory.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121592422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Published data on avionic fatigue life and high-temperature endurance were used to develop straight-line relationships between stress amplitudes and life at given amplitudes for four part types: a chassis, a plated-through hole, an integrated circuit (IC), and a non-IC piece part. Design-life-distributions for four accelerated reliability test programs were derived for the same item categories using the same straight-line relationships between stress and life. The tests involved 15 specimens and approximately 40000 accelerated test hours. A test-life observation was multiplied by the ratio between predicted usage life mean for the design configuration and predicted test-life mean for the test configuration being observed. A product limit technique was used to treat censorship (observations of test end without relevant failure). The resulting test data distribution was used to predict the failure-free operation period and the mean time between failures for the new design.<>
{"title":"Using test data to predict avionics integrity","authors":"G. Benz","doi":"10.1109/ARMS.1990.67920","DOIUrl":"https://doi.org/10.1109/ARMS.1990.67920","url":null,"abstract":"Published data on avionic fatigue life and high-temperature endurance were used to develop straight-line relationships between stress amplitudes and life at given amplitudes for four part types: a chassis, a plated-through hole, an integrated circuit (IC), and a non-IC piece part. Design-life-distributions for four accelerated reliability test programs were derived for the same item categories using the same straight-line relationships between stress and life. The tests involved 15 specimens and approximately 40000 accelerated test hours. A test-life observation was multiplied by the ratio between predicted usage life mean for the design configuration and predicted test-life mean for the test configuration being observed. A product limit technique was used to treat censorship (observations of test end without relevant failure). The resulting test data distribution was used to predict the failure-free operation period and the mean time between failures for the new design.<<ETX>>","PeriodicalId":383597,"journal":{"name":"Annual Proceedings on Reliability and Maintainability Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130477861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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