2008 Annual Reliability and Maintainability Symposium最新文献

{"title":"System reliability and condition based maintenance","authors":"J. Banks, K. Reichard, M. Drake","doi":"10.1109/RAMS.2008.4925833","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925833","url":null,"abstract":"The need for high system reliability and platform availability in DoD assets is an increasing necessity with the continuing combat deployment of service personnel coupled with the high usage rates for the equipment that they rely upon to complete their mission. In general, reliability is obtained through a variety of measures including precision design, reduction in the number of parts required for functionality and component/system redundancy. The availability of an asset is affected by both reliability and maintainability. There is a significant amount of anecdotal evidence that condition based maintenance enabled by embedded diagnostics and prognostics can directly improve maintainability but not reliability. The focus of this paper is to discuss the impact of reliability on key platform performance parameters and to compare the impact of embedded system health monitoring on those same key performance parameters. If the reliability of a component is defined by its capability to function to a required standard when requested, then health management technology should be able to provide the same benefit as increasing inherent reliability. If a functional but faulted component is replaced before it fails, when the platform is not required to be operational, then the availability of the component and the asset will be maintained or increased with the same inherent reliability. The paper discusses the requirements imposed on the embedded health monitoring system in terms of replacing investments in increased inherent reliability with investments in system health monitoring. This is a well known scenario, but difficult to implement effectively in a real world environment. The effort will require reliability engineers and health management technologists to work together to accomplish this common objective. The context for the application of this concept is the U.S. Army Heavy Brigade Combat Team - Condition Based Reliability Analysis (HBCT- COBRA) program. The objective of this program is to increase the reliability and availability of the HBCT platforms through implementation of embedded diagnostics, prognostics and CBM methodology.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129621115","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}

{"title":"A case study on network reliability analysis for systems with non-independent paths","authors":"Meng-Lai Yin, R. Arellano","doi":"10.1109/RAMS.2008.4925779","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925779","url":null,"abstract":"The problem addressed here is the complexity in reliability modeling for network systems with non-independent paths. Dependency usually is dealt with models with high fidelity and high complexity, which leads to the difficulties in model construction and solution. A pivoting method is proposed here to effectively handle the complexity. The presentation starts from the discussion of independent cases, where combinatorial approach such as reliability block diagram method can be applied. Networks with non-independent paths are then addressed, with the pivoting method applied. This approach is applicable to modeling complex systems beyond the example presented here, i.e., network systems with non-independent paths. Any system with components that cause the dependencies can be analyzed using the approach proposed.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132252812","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}

{"title":"Modeling and simulation methodology of the operational availability and logistics using Extended Colored Stochastic Petri Nets — an astronautics case study","authors":"S. Nebel, B. Bertsche","doi":"10.1109/RAMS.2008.4925835","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925835","url":null,"abstract":"This paper presents a comprehensive methodology for the modeling and analysis of complex systems. The model incorporates an extended colored stochastic Petri net and a reliability block diagram in a conjoint modeling procedure which allows a close-to-reality representation of a complex systems behavior. The application of the modeling and analysis methodology has been demonstrated. A fault-redundant system aboard a space station has been considered in a case study. For verification purpose the results of the simulation have been compared with the analytic solutions of another publication. The operational reliability characteristics of the system have been analyzed in a simulation study, the influence of the maintenance strategy on the operation availability and the spare part demand has been considered. The methodology allows considering the interdependencies of reliability, availability, maintenance and logistics within a system and its optimization. The methodology also allows decision support, for example in case of a situational adaption of the maintenance strategy at any point of time.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132841274","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}

{"title":"A study on optimal age replacement of dozer engines","authors":"P. Prasad, K. Rao","doi":"10.1109/RAMS.2008.4925765","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925765","url":null,"abstract":"In this paper, the concepts and methods of total time on test (TTT) plots are discussed. The failure data of two groups of electro-mechanical equipment (indigenous and imported dozer engines) are used to draw TTT plots, which indicate health of equipment in terms of failure rate. The optimum replacement interval is obtained for the equipment with increasing failure rate depending on the type of the data i.e. independently and identically distributed (i.i.d) or not. Graphical and analytical tests are used to confirm the nature and trend of the data. Non-parametric methods like Kaplan-Meir estimate and Nelson estimate are used to evaluate cumulative distribution function and scaled TTT to construct the plots. Parametric methods like Weibull and power law process models are used to verify the graphical results.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131926859","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}

{"title":"Optical monitoring system availability optimization via semi-Markov processes and genetic algorithms","authors":"M. das Chagas Moura, P. Firmino, E. Droguett, C.M. Jacinto","doi":"10.1109/RAMS.2008.4925810","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925810","url":null,"abstract":"System availability optimization is one of the main issues to oil production managers: the greater the system availability the greater the production profits are. Provided that preventive maintenance actions promote rejuvenation impact on availability indicator, this paper proposes an approach to maximize the mean availability by identifying an optimal maintenance policy for downhole optical monitoring systems, which are modeled according to non-homogeneous semi-Markov processes. In order to solve the resulting optimization problem constrained by system performance costs, new real-coded GA operators are also presented. The proposed approach is exemplified by means of an application to a real scenario in onshore oil wells in Brazil.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130514884","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}

{"title":"Identifying factors influencing reliability of professional systems","authors":"A. Balasubramanian, K. Kevrekidis, P. Sonnemans, M. Newby","doi":"10.1109/RAMS.2008.4925771","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925771","url":null,"abstract":"Modern product development strategies call for a more proactive approach to fight intense global competition in terms of technological innovation, shorter time to market, quality and reliability and accommodative price. From a reliability engineering perspective, development managers would like to estimate as early as possible how reliably the product is going to behave in the field, so they can then focus on system reliability improvement. To steer such a reliability driven development process, one of the important aspects in predicting the reliability behavior of a new product, is to know the factors that may influence its field performance. In this paper, two methods are proposed for identifying reliability factors and their significance in influencing the reliability of the product.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131216277","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}

{"title":"Reliability evaluation and application for systems with different phases","authors":"Huairui Guo, A. Mettas, A. Monteforte","doi":"10.1109/RAMS.2008.4925760","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925760","url":null,"abstract":"Many systems are multi-phase mission systems. During different phases, the system reliability configuration, reliability requirements and operation environment can be different. For example, some components may change from active status to standby or the system reliability configuration may change from serial to parallel. In addition to configuration changes, the system may be exposed to different stress conditions; therefore, the time to failure distribution of some components will change due to the change in stress. In general, systems that operate under different phases are considered as dynamic systems. A way to estimate the reliability and availability of such systems is needed. In this paper, a systematic procedure of applying accelerated life tests and simulation to analyze the reliability and availability of such dynamic systems is first proposed. Methods for solving both non-repairable and repairable systems are provided. For non-repairable systems, an analytical solution based on cumulative damage theory is discussed. Therefore, the exponential assumption, which is used in many existing methods, is not required in the proposed method. In addition to the analytical solution, a cumulative- damage-based simulation solution is also provided. For repairable systems, based on different scenarios in real applications, the repairable phased-mission system is classified into three categories. Because of the complexity of the problem, only simulation results are given for repairable systems. The proposed systematic procedure of applying accelerated life tests in phased-mission system analysis provides a general guideline for dealing with real-world applications. The cumulative-damage-based analytical and simulation method provide a practical and useful approach for solving phased-mission system problems. The classification of repairable phased-mission systems gives a clear overview of the phased-mission systems and makes the analysis of complex real applications easier.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124051491","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}

{"title":"Optimum plans for step-stress accelerated life tests at higher usage rates","authors":"Guangbin Yang","doi":"10.1109/RAMS.2008.4925804","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925804","url":null,"abstract":"The life of some products is measured by usage, e.g., mileage and cycles. In accelerated testing, these products are usually run at elevated stress levels and higher usage rates to shorten test length. The increase in usage rate may prolong or shorten usage to failure. In this paper, a model that relates life to stress and usage rate is described. For the model, this paper develops 3-step step-stress optimum test plans, which choose the optimal step-change times by minimizing the asymptotic variance of the estimate of the log mean life at a design stress and usual usage rate. The sensitivity of the test plans to preestimates is evaluated, and the results show that the plans are robust. This paper also presents the maximum likelihood estimates of model parameters and the mean life at the design stress and usual usage rate, and their confidence intervals. The proposed method is applied to estimate the reliability of a compact solenoid valve.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124230095","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}

{"title":"Analysis of decisions involved in offering a product warranty","authors":"B. LeBlanc","doi":"10.1109/RAMS.2008.4925793","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925793","url":null,"abstract":"Every day, competitive proposals are submitted to the Department of Defense for anything ranging from weapons to service and support contracts to dual-band ship-based radar systems. A company's competitiveness against other potential contractors is riding on its ability to design superior products at an affordable cost to the customer. Part of offering an affordable product comes in the form of a warranty. It is difficult to quantify the risks and rewards of offering a warranty. Reliability engineers are often asked to evaluate the risk of offering a warranty on a system. Offering a warranty on an unproven technology is obviously very risky. However, not providing some form of guarantee on their products also comes with risk, as it infers added life cycle costs to the customer, particularly if the competition is offering a warranty. The goal of any company is to identify a way to examine and manage risks associated with offering a warranty, versus not offering a warranty. A working model was developed, which can be used to evaluate optimal warranty terms and conditions to maximize net present value (NPV). The NPV is calculated from a series of future cash flows derived from product sales and expenses associated with warranty program costs. The Warranty Costs and Decision Model can be refined continuously and be improved for actual use by any defense contractor. Additional data could be collected to minimize the amount of assumptions, such as the probability of winning a contract under certain conditions, etc. The current model as presented, however, demonstrates the power of the @RISK software tool, and the type of complex analyses that can be easily performed. As defense contractors continue to try to improve their proposal processes and contract win percentages, development of a warranty cost and risk analysis tool, like the one presented here, offers an edge over the competition. Being able to quantify risk and opportunity associated with many unknowns is advantageous over making those types of decisions based on \"gut feel\" and intuition alone.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117323943","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}

{"title":"Fault propagation analysis for complex system based on small-world network model","authors":"Jianmin Gao, Guo Li, Zhiyong Gao","doi":"10.1109/RAMS.2008.4925822","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925822","url":null,"abstract":"The spreading of faults and serious failures in many large-scale engineering systems is today one of the issues of the highest concern. This paper presents a novel method for modeling the fault propagation behaviors from the perspective of complex network theory. By focusing essentially on the topological structure properties of the underlying system network, several principles that are capable of assessing the safety characteristics of the network nodes are proposed. Rather than the probabilistic approach, the fault propagation intensity considering the network statistical information is defined as the weight of the link between the nodes. Subsequently, the critical nodes and the fault propagation paths with high risk are obtained through the qualitative fault propagation analysis. A case study of sym-tetramethyl benzene (STBZ) production system is provided to illustrate the feasibility of the proposed approach, and to verify the efficiency to discover the system vulnerability. Research shows that the safety performance of a complex system is indeed affected by the availability of some critical nodes, which is a helpful method to the safety assessment and failure prevention.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127830534","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}