Operational reliability and maintainability

Adequate space should be allowed for the maintenance of the incineration system, especiaUy around components that may become contaminated and require frequent replacement. Proper shielding, either permanent or portable, should be available to protect workers during operation and maintenance. Provisions for remotely controlled maintenance of the system should be considered. 

The design of the system should include provisions to facilitate component replacement, adjustment and proper servicing. Many components may not need to have the fiill lifetime planned for the entire incineration system. Items such as refractory components, fan bearings and seals, pump bearings and seals, and instrumentation will require the determination of a replacement schedule. 

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Verify long-term, continuous operability, reliability, and maintainability (i.e., operation of the full length of the test without unintended shutdown)... 

Regardless of the terms and labels that are used, the aim is always to optimize human efficiency, effectiveness, health, safety, and well-being, within the context of overall system performance operability, reliability, and maintainability. 

Design validation may take the form of qualification tests which stress the product up to and beyond design limits - beta tests where products are supplied to several typical users on trial in order to gather operational performance data, performance trials, and reliability and maintainability trials where products are put on test for prolonged periods to simulate usage conditions. 

In many ways factories, at least, ARE like they used to be. This is not surprising, as human nature is a common factor. We have better equipment but may be just as likely as in the past to cut corners when we design, construct, operate, test, and maintain it, perhaps more likely as there are fewer of us to keep our eyes open as we go round the plant and to follow up unusual observations. We have access to more knowledge than our parents and grandparents, but are we any more thorough and reliable ... 

These systems must be designed so as to accommodate continual change. They should easily accommodate frequent changes in formulations and reactor hardware. They must be able to control complex operations involving simultaneous tasks. Contrasting with these requirements, the software must be easily maintained, operate reliably, and be easy to use by laboratory personnel. 

The general framework presented here on the model development side, the issues of knowledge representation in the form of systematie eomposition, ontology, and quantity representaion was involved. On the model analysis side issues involving the automatie evaluation and presentation of simulation results. The plant simulation model should mirror the behaviour of a eomplex plant subjeet to eonstraints in feedstoek, produets, equipment eapaeities, operational parameters, and utilities eonsumptions. The life eyele eoneept may lead to a reliable and maintainable tool. 

Program. Based on IMS technology, the ICAM upgrades the CAM with improved reliability and maintainability. It is a handheld device for real-time detection of low levels of nerve and mustard vapors and is capable of both day and night operation. More than 6,000 ICAMs have been procured to date. 

Achieve integrated operation of the complete system and conduct a nominal two-year test program to determine reliability and maintainability... 

The need for a reliability and maintainability program must be anticipated right from the beginning. The need for such programs cannot be overemphasized. These programs are justified based on specific system requirements in terms of life-cycle cost and other operational requirements. As already mentioned, the effectiveness of a system is determined by its reliability and maintainability characteristics. 

Availability is defined as the probability that a system is operating satisfactorily at any point in time. Availability considers only the operating time and downtime, thus excluding the idle time. Therefore, it is a measure of the ratio of operating time of the system to the operating time plus the downtime. Availability is a function of both the reliability and maintainability of the system. 

The other approach is to use discrete event analysis. This approach is able to handle the real-world complexity of most systems. Referring to Example 1 in Chapter 1, it may be found that the availability of Pumps, P-101 A/B is not a simple number but varies according to many time-dependent factors such as when they were most recently inspected, the availability of spare parts and the operating conditions. Factors such as these can materially affect the reliability and maintainability of the pumps, often in ways that are impossible to model deterministically. 

The outcome of a reliable and maintainable system is really the primary goal. This goal, typically referred to as availability, is essentially a measurement of the ability to operate a fully functional system. Availability is expressed as a ratio, comparing the amount of time that a system is up to the total time measured. 

Reliability and maintainability analysis, based on breakdown, repair, and periodic maintenance statistics obtained for each plant item (or even on sensible guesses from experienced people). In conjunction with economic data, the model is used to predict plant availability and economic performance while taking into account the probability of failure of individual components and the repair time. The model may be used to make optimum choices on the provision of standby equipment, equipment enhancement, operational flexibility enhancement (including optimizing the period between overhauls), maintenance facilities, intermediate tankage or stockpile capacity, and capacity margins for individual equipment items. 

Enhance the public perception of safety Reduce the need for operator action Maximise system reliability and maintainability Make maximum use of existing technology Reduce the time needed for construction Competitive cost... 

Kramer, R.A. 1991. Analytic and operational consideration of electric system reliability. Proceedings of the Reliability and Maintainability Symposium. IEEE, New York. 

Availability typically expressed as the fraction of time the equipment is able to perform its intended function under given operating conditions. Availability is a function of reliability and maintainability. 

Transport systems are characterized usually for its flexibility, huge quantity of equipment and application. In effect the feature of load sharing, allows obtaining the required capacity on the basis of the sum of the available equipment even operating in a lower load than required. The case of overcapacity is characterized by having more capacity installed than required, by which there exists a series of combinations that allow satisfy the required capacity. The above condition requires that the equipment can operate at different work levels. As a conclusion of this problem, we can set up that the impact of each component is variable and depends on its required load as well as its reliability and maintainability behavior, as so also of the characteristics of each one of the equipment that constitutes the system. For the previously situation mentioned above, the availability assessment is a complex system to carry out and follow up it is proposed a methodology for its validation. 

Within the last fifty years the performance requirements for technical objects and systems were supplemented with customer expectations (quality), abilities to prevent the loss of the object properties in operation time (reliability and maintainability), protection against the effects of undesirable events (safety and security) and the ability to restore performance (resilience). The need to adapt the operation of complex systems in such an uncertain and volatile environment has caused the necessity to formulate new and well established achievements associated with modeling, testing and evaluation of these properties. The concept of a complex system applies not only to the technical ones but also the infrastructure of major importance for social life such as transportation and logistics systems, buildings, power systems, water distribution systems or health services. 

Availability is a measure of the degree to which an item is ready to operate when called for use at an unknown (random) time. Availability is the probability that a system is not failed or undergoing repair action when it needs to be used. It is a performance criterion for repairable systems that accounts for both the reliability and maintainability properties of a component or system. 

The Royal Navy has introduced reliability and maintainability engineering concepts in order to ensure that modem warships are capable of a high combat availability at optimum cost (Gosden and Galpin (1999)). The application of these methods has been progressively extended from consideration of the operational phase and maintenance planning to the design phase. 

The purpose of the Maintenance Process is to sustain the capability of the system to provide a service. This process monitors the system s capability to deliver services records problems for analysis takes corrective, adaptive, perfective, and preventive actions and confirms restored capability. Early in the Concept stage of the life cycle, reliability and maintainability requirements were identified in the Design Process. The Maintenance Process must ensure that these requirements are accurate as designed and, if necessary, changes are properly documented. As with the Operations Process, the Maintenance Process is performed in the Utilization Stage/ Support Stage of the system life cycle. 

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