Outage, definition

The relationships between the importance measures is based on the assumption that the systems are not reconfigured in response to a component outage. If this is done, the basic definition of the importance measure is still valid but there is not such a simple relationship. Disregarding this complication, some interpretations of the importances may be made. The Bimbaum Importance is the risk that results when the i-th system has failed (i.e., it is the A, term in Equation 2.8-9). Inspection Importance and RRWI are the risk due to accident sequences containing the i-th system. Fussell- Vesely Importance is similar except it is divided by the risk so may be interpreted as the fraction of the total risk that is in the sequences contains the Q-th system. The Risk Achievement Worth Ratio (RAWR) is the ratio of the risk with system 1 failed to the total risk and is necessarily greater than one. The Risk Achievement Worth Increment (RAWI) is the incremental risk increase if system 1 fails and the Risk Reduction Worth Ratio (RRWR) is the fraction by which the risk is reduced if system 1 were infallible. 

Develop timetable for shutdown The management team should establish a macro-level schedule for the outage. Without complete planning, a definitive timeline can not be established, but the team should establish specific milestones that must be met. 

The first phase is a clear definition of the scope of work that is to be performed during the shutdown or maintenance outage. This definition must be more than a macro-level listing of the major tasks that are to be performed. Instead, each of these major or macro-level tasks must be fully defined. The purpose of this procedure is to provide an effective method of planning, material control, and follow-up of repetitive, non-repetitive, and capital shutdown work. 

Loss of software support for aging versions of business critical systems can create significant business continuity and regulatory risks. Pharmaceutical and healthcare companies should provide a definitive statement on how they will maintain critical systems where support has historically been provided by third parties but that support is no longer available or set to expire. Measures need to be established to prevent adverse impact to product quality and product data and how they will ensure business continuity during any system outage. 

It will be observed that none of these events did endanger reactor safety. On the other hand one (no.40) definitely compromised any hope to cover the plant operating costs, for the repair could not restore hot irradiated fuel storage capacity and compelled the operator thereafter to wait for the decay power to subside before unloading the core, meaning long outages. 

Definition Transient and oscillatory overvoltage Momentary undervoltage or overvoltage Power outage... 

For revealed failures the MDT consists of the active mean time to repair (MTTR) PLUS any logistic delays (e.g., travel, site access, spares procurement, administration). For unrevealed failures the MDT is related to the proof-test interval (T), PLUS the active MTTR, PLUS any logistic delays. The way in which failure is defined determines, to some extent, what is included in the down time. If the unavailability of a process is confined to failures while production is in progress then outage due to scheduled preventive maintenance is not included in the definition of failure. However, the definition of dormant failures of redundant units affects the overall unavailability (as calculated by the equations in the next Section). 

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