High-reliability systems

Stopes-Heerlen Classification, 6 707t High reliability systems, for safety shutdowns, 20 671... 

And yet, for more them four years after its very successful First National Bank of Omaha project, SurePower was not able to sell a second high-reliability system. The interrelated reasons for this go to the heart of the reason why fuel cells will have difficulty using reliability problems as a path to commercialization. 

The effective iterative algorithm to solve a maintenance optimization problem of a highly reliable system... 

For a repairable highly reliable system, the question is often when to replace or overhaul an old system. Replacing (orrenewing) the system too often is expensive, but an old deteriorating system may fail often requiring many repairs. The objective is to choose the time between renewals to minimize the cost. There are many possible cost models for this scenario, but we will suppose a simple linear cost model. 

New methodology for exact reliability quantification of highly reliable systems with maintenance was introduced in (Bris 2008a). It assumes that the system structure is mathematically represented by the use of directed acyclic graph (AG), see more details in (Bris 2008b). Terminal nodes of the AG that represent system components are established by the definition of deterministic or stochastic process, to which they are subordinate. From them we can compute a time dependent unavailability function, of individual terminal nodes. Finally a correspondent time dependent imavailability function U(x,t) of the highest node (SS node or top event in classic PRA model) which represents rehabdity behaviour of the whole system may be found. It is clear that U(x,t) < Us(x). 

The downtime of the yth component due to testing has been neglected as well as probability of human error. The purpose of the simplification is in that the algorithm is first of all intended for the highly reliable systems. 

In spite of the fact that the method is only one-objective method, in comparison with other multiobjective methods it enables optimization and followup quantification of highly reliable systems (see Figs 5-6). The method was demonstrated on the simplified system HPIS from practice. CPU time in all computation runs did not exceed 1 min. 

Bris, R. 2008a. Exact reliability quantification of highly reliable systems with maintenance. In Safety, Reliability and Risk Analysis Theory, Methods and Applications - Mar-torell et al. (eds), Taylor Francis Group, 489-496. ISBN 978-0-415-48513-5. 

Vulnerable System Large-Scale System High-Reliability System... 

Another feature of the communicating function is battery authentication with the device. In high-reliability systems such as medical equipment, nonoriginal equipment batteries can cause poor performance or worse and are prevented from being used in the end equipment. One method to prevent after-market or other substitute battery packs from being used is to employ an authentication technique via communication. The host device will issue commands to the battery pack over the communication interface and using one of several standards options, get authentication information from the battery pack. If the authentication is successful (the correct keys are used to return a coded... 

Highly reliable systems of the marine nuclear reactor industry and operating NPPs ... 

The application of highly-reliable systems proven in operation of the shipboard reactor installations and contemporary NPPs and... 

Highly reliable system with high availability... 

The diverse software problem. In extremely high-reliability systems such as nuclear reactor shutdown systems, as we shall see, two diverse high-integrity protection (safety) systems may be required. The question is, is it alright for... 

Sneak circuit analysis (SCA) is used for evaluating electrical circuits, with the intention of identifying latent (sneak) circuits and conditions that inhibit desired functions without component failure having occurred. Sneak circuits can occur in all types of electrical and electronic systems, so SCA is required for high-reliability systems. Sneak circuits can create sneak paths (which allow current to flow along an unexpected route) or sneak timing (which causes functions to be inhibited or to occur unexpectedly). 

However equations (3) and (4) cannot be regarded as anything but helpful guides, since in cases where highly reliable systems are sought, common-mode failures will dominate errors in maintenance, errors in design, environmental conditions etc. (Reference 8) software design errors (Reference 9). 

The systems we are faced with are, most of the time, not uniform. Modem high reliability systems are often distributed, and consequently, the performance of their constiments and subsystems differ in mai aspects (environment, speed, timing), at different places throughout the system. 

Highly reliable systems of the nuclear propulsion reactors and of the state-of-the-art NPPs are used. 

The high reliable systems undergo Reliability Centered Maintenance (RCM) strategy that is implemented to optimize the maintenance program. In aviation the strategy based on RCM for assessment maintenance tasks was developed and is involving as MSG-3 which implement the newest research achievements. 

Simulation of highly reliable systems with extremely low error probability Employment in early research and development stages, when a field data analysis cannot be conducted... 

Robust and highly reliable systems for adequate cooling of safety-relevant components and structures,... 

Improve mean time between failures (MTBF) under the reduced manning environment. This approach improves MTBF through actions such as designing or choosing highly reliable system parts and designing the interfaces to optimize the use of these parts. 

Weick, K. E. (1989). Mental models of high reliability systems. Industrial Crisis Quarterly, 3, 127-142. 

Resilience model HRO model High Reliability Systems Ultra-safe model... 

In between the two ends, burnout effect on safety performance can be moderated through mediation. The individual s degree of direct involvement in safety provision and the quality of the workers and work processes would have different impact on safety performance. A high reliability system is likely to compensate the individual lapses. On the other hand, a low reliability work system with poor quality workforce and processes compound the burnout effect and aggravate the poor safety conditions. 

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