Annual Symposium Reliability and Maintainability, 2004 - RAMS最新文献_第3页

Development of the risk oriented program optimization tool (ROPOT) for orbital space plane design concepts 面向风险的轨道空间平面设计方案优化工具(ROPOT)的开发

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285422

B. Putney, J. Fragola

{"title":"Development of the risk oriented program optimization tool (ROPOT) for orbital space plane design concepts","authors":"B. Putney, J. Fragola","doi":"10.1109/RAMS.2004.1285422","DOIUrl":"https://doi.org/10.1109/RAMS.2004.1285422","url":null,"abstract":"The preliminary design phase of any program is the key to its eventual successful development. The more advanced a design, the more this tends to be true. For this reason, the preliminary design phase is particularly important in the design of aerospace systems. Errors in preliminary design tend to be fundamental and tend to cause programs to be abandoned, or to be changed fundamentally, and at great cost later in the design development. In order to facilitate the identification of attractive design regimes, the NASA Ames Research Center initiated a project, supporting the 2/sup nd/ generation reusable launch vehicle (RLV) Program, to develop an advanced suite of conceptual design tools. The tool, called risk oriented program optimization tool (ROPOT) was developed for evaluation of reusable space transportation system (RSTS) conceptual analysis. The ROPOT tool is a modular \"lego-block\" approach that is built on risk drivers from the space shuttle. This paper illustrates how this tool was adapted and applied to the decision-making about future space transportation system architectures, including new orbital space plane designs that are to be launched on the new evolved expendable launch vehicles. ROPOT has been further developed to provide the capability to explore crew survival capabilities of the vehicles throughout the mission, and develop insights and concerning the key trades involving performance, cost, crew safety and developmental risk. The tool demonstrated the ability to capture the key trades necessary to make informed decisions concerning alternative vehicle concepts, clearly identify strengths and weaknesses of design alternatives, and identify the most fruitful areas for achieving overall benefits. The results of this effort demonstrate the ability of ROPOT to be easily adapted to evaluate a broad range of vehicle types ranging from fully-reusable advanced concepts of the 2/sup nd/ generation program, to near term expendable vehicles.","PeriodicalId":270494,"journal":{"name":"Annual Symposium Reliability and Maintainability, 2004 - RAMS","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131044835","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}

引用次数: 2

Disk drive vintage and its effect on reliability 磁盘驱动器老化及其对可靠性的影响

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285441

S. Shah, J. Elerath

{"title":"Disk drive vintage and its effect on reliability","authors":"S. Shah, J. Elerath","doi":"10.1109/RAMS.2004.1285441","DOIUrl":"https://doi.org/10.1109/RAMS.2004.1285441","url":null,"abstract":"Field failure data for 3 disk drive families from 3 drive manufacturers is analyzed. The analyses illustrate the effects of design and manufacturing process improvements implemented throughout the drive's production life on the reliability of disk drives. Also, the resultant effect of convolution of different shipment volumes and different vintage drives reliability is studied. Two drive families show distinct reliability differences between drive vintages. The newer vintage drives are more reliable than the older vintage drives. One interesting observation is the ratio of average failure rate during the first three or four months of production to the average failure rate later in time when failure rate has stabilized. This ratio is observed to be between 2 and 3. One drive family, on the other hand, showed almost no difference in the reliability between vintages because of a dominant failure mechanism that was unaffected by most of the design and manufacturing process changes implemented. Also, if the shipment volumes are high in the beginning period of the drive shipments the overall reliability of the field population may be lower due to a high contribution of the early vintage drives with higher failure rates.","PeriodicalId":270494,"journal":{"name":"Annual Symposium Reliability and Maintainability, 2004 - RAMS","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122584379","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}

引用次数: 29

Planning of step-stress accelerated degradation test 阶梯应力加速退化试验的规划

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285462

L. Tang, G. Yang, M. Xie

{"title":"Planning of step-stress accelerated degradation test","authors":"L. Tang, G. Yang, M. Xie","doi":"10.1109/RAMS.2004.1285462","DOIUrl":"https://doi.org/10.1109/RAMS.2004.1285462","url":null,"abstract":"Estimating the long term performance of highly reliable products has been a difficult problem as accelerated life testing (ALT), which involves testing at highly elevated stresses, often results in too few failures for drawing useful inferences. To overcome this problem, accelerated degradation testing (ADT) has been proposed as a means to predict performance for highly reliable products. It requires one to identify a performance measure that would exhibit degradation and to monitor it over time. Product reliability can then be inferred from the degradation paths without the need of observing actual failures. Although physical failures are not needed in ADT, one usually defines failure as the first time when the degradation process exceeds a pre-specified threshold, so that the degradation path can be correlated to product reliability. As a result, reliability information of a product is embedded in degradation paths of units tested under ADT. In this paper, we look into planning of an ADT in which the test stress is increased in steps from lower stress to higher stress during the test, so that specimens are gradually conditioned to the stressed environment thus avoiding over-stressing. Our objective is to minimize the cost of testing, which is a function of sample size, test duration and number of inspections, as well as obtaining a reliability estimate of a requisite level of precision. Data from degradation paths are used to characterize the appropriate stochastic model underlying the product degradation process. We then derive the maximum likelihood estimators and the mean life at the use stress and its asymptotic variance. This variance is then used as a constraint, in a test plan which minimizes the testing cost. The optimal test plan gives the optimal sample size, number of inspections at each intermediate stress level and number of total inspections.","PeriodicalId":270494,"journal":{"name":"Annual Symposium Reliability and Maintainability, 2004 - RAMS","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115653728","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}

引用次数: 84

Modeling multiphased missions using stochastic Petri nets with aging tokens 带老化令牌的随机Petri网多阶段任务建模

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285453

V. Volovoi

引用次数: 12

Failure modes and effects analysis during design of computer software 计算机软件设计中的失效模式及影响分析

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285448

N. Ozarin

{"title":"Failure modes and effects analysis during design of computer software","authors":"N. Ozarin","doi":"10.1109/RAMS.2004.1285448","DOIUrl":"https://doi.org/10.1109/RAMS.2004.1285448","url":null,"abstract":"Performing FMEA on computer software presents problems and challenges not found in FMEA of electronic hardware. Contractual directions are usually very limited or nonexistent, leaving the analyst to establish and tailor guidelines needed for a particular analysis. Where code is unavailable or off limits to the analysis, the FMEA is of limited usefulness but can still contribute to a more reliable system design. Unfortunately, many reliability analysts have more difficulty developing an approach to software analysis than doing it. An understanding of the software design process and a discussion of various approaches to software design FMEA is presented to make development of an appropriate approach and performance of the analysis itself easier to understand. Moving from the lowest level of analysis to the highest level typically from the method level to the module or package level - a FMEA becomes less accurate, less precise, and less informative, while the process becomes less difficult, less tedious, and less time-consuming. Moving from the lowest level of analysis to the highest also means a FMEA is based increasingly on the stated intent of the software designers and less on the actual product behavior. For any analysis above the code level, the analyst's conclusions about effects at each level is unfortunately be no better than the descriptions that the software designers provide.","PeriodicalId":270494,"journal":{"name":"Annual Symposium Reliability and Maintainability, 2004 - RAMS","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134139695","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}

引用次数: 25

Requirements based system level risk modeling 基于需求的系统级风险建模

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285497

L. Meshkat, S. Cornford, M. Feather

{"title":"Requirements based system level risk modeling","authors":"L. Meshkat, S. Cornford, M. Feather","doi":"10.1109/RAMS.2004.1285497","DOIUrl":"https://doi.org/10.1109/RAMS.2004.1285497","url":null,"abstract":"Space exploration missions are often characterized by multiple phases and each phase in turn satisfies some objective or requirement. The success of the mission is measured by the degree to which these requirements are satisfied. Missions either aim to demonstrate a new technology, or to obtain new science data or a combination of both of these. During the mission design process, numerous trade studies are conducted between cost, performance and risk. At a very high level, the goal is to maximize the probability of achieving the most science return (or demonstrating the most technology) at the least possible cost. We consider the problem of maximizing this probability by quantifying the degree of importance of each requirement and it's probability of being satisfied. The probability of a requirement being satisfied, in turn, is assessed by finding the aggregate of the probability of all the possible events that could prevent it from being satisfied. We assume a complete list of the requirements, the relevant risk elements and their probability of occurrence and the quantified effect of the risk elements on the requirements. In order to assess the degree to which each requirement is satisfied, we need to determine the effect of the various risk elements on the requirement. The complexity arises due to the fact that various risk elements that effect a requirement in question are not necessarily independent. Moreover, in order to compute the weighted average of the requirements, it's important to take into consideration their dependencies. Therefore we carefully define the relationships between the elements within each category (intra-category) and the elements between the two different categories of risk and requirements (inter-category).","PeriodicalId":270494,"journal":{"name":"Annual Symposium Reliability and Maintainability, 2004 - RAMS","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117148941","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}

引用次数: 3

Effect of element initialization in synchronous networked control system to control quality 同步网络化控制系统中元件初始化对控制质量的影响

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285436

J. Ligusova, J. Thiriet, J. Ligus, P. Barger

引用次数: 14

System reliability assessment using covariate theory 用协变量理论进行系统可靠性评估

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285417

J. Wallace, D. Mavris, D. Schrage

引用次数: 3

Demonstrating ultra-high component reliability 展示超高的组件可靠性

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285475

J. McLinn

{"title":"Demonstrating ultra-high component reliability","authors":"J. McLinn","doi":"10.1109/RAMS.2004.1285475","DOIUrl":"https://doi.org/10.1109/RAMS.2004.1285475","url":null,"abstract":"The ever-increasing desire/need to produce high reliability systems of long life has lead to ultra-high reliability requirements for supplied components and assemblies. Requirements such as 99% survivors at 5 years or 90% survivors after 20 years are very difficult to demonstrate in the laboratory in a reasonable period of time. What alternatives exist to assure that the desired component reliability is present? The purpose of this paper is to outline a coherent series of steps that lead to the ability to demonstrate conformance with ultra-high reliability requirements of components and assemblies. This process begins with a statement defining ultra-high reliability requirements. Next, a short discussion about the ability to achieve ultra-high reliability component requirements sets the stage for examples. The first example is mechanical and the second is an electronic assembly. Both are explored in detail in order to show the full problem and why simple life test approaches may fail to assure the desired reliability is present. During the paper, consideration for product development systems, safety, warranty issues, quality and system reliability concerns are briefly discussed. These two examples explore a series of steps that can achieve and/or demonstrate the desired reliability without resorting to \"brute-force\", costly, time-consuming and/or possibly fallible test approaches. Lastly, the paper completes the examples by offering a systemic approach that can serve as a road map for most situations and companies.","PeriodicalId":270494,"journal":{"name":"Annual Symposium Reliability and Maintainability, 2004 - RAMS","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129183350","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}

引用次数: 0

Dimensioning of product support: issues, challenges, and opportunities 产品支持的维度:问题、挑战和机遇

Annual Symposium Reliability and Maintainability, 2004 - RAMS Pub Date : 2004-08-24 DOI: 10.1109/RAMS.2004.1285507

T. Markeset, U. Kumar

{"title":"Dimensioning of product support: issues, challenges, and opportunities","authors":"T. Markeset, U. Kumar","doi":"10.1109/RAMS.2004.1285507","DOIUrl":"https://doi.org/10.1109/RAMS.2004.1285507","url":null,"abstract":"Dimensioning of product support is influenced by the product's designed-in characteristics, especially those related to RAMS. Based on a case study conducted in a manufacturing company that produces advanced automated production systems, this paper examines issues related to dimensioning of product support for advanced industrial products. The focus is mainly on the investigating engineering factors/parameters that influence product support strategy. In the case study, we examine various approaches and methods to integrate RAMS in combination with LCC in design work processes to arrive at the most cost effective product support strategy for industrial systems and components. Various aspects of product support strategies for functional products where the customer buys only the performance, not the physical product is studied and analyzed. In the conventional product scenario, the manufacturer benefits from selling support services, whilst this profit generating process becomes a cost and liability in the functional product scenario. It is concluded that the product support strategy for functional products will differ considerably compared to that for conventional products.","PeriodicalId":270494,"journal":{"name":"Annual Symposium Reliability and Maintainability, 2004 - RAMS","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114938118","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}

引用次数: 41