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Identifiability single point

The FMEA evaluates reliability and identifies single-point failures. It can be performed at different levels and thus at different times in the life cycle. [Pg.155]

The FMEA evaluates the reliability of the design and identifies single-point failures that can lead to system failure. It also determines the possible effects of all potential failures and thus can aid in identifying failures with safety significance. It provides a cause-effect relationship for failures, some of which may be safety related. Failure rates or other reliability statistics can be used to quantify the FMEA. [Pg.156]

In any event, after the tree has been developed consistent with the ground rules for the project, the next step is to analyze the tree to determine weak spots in the system, identify single-point failures, evaluate redundancy, and seek appropriate methods of improving the reliability and safety of the system. [Pg.174]

The second and more common hardware FMEA examines actual system assemblies, subassemblies, individual components, and other related system hardware. This analysis should also be performed at the earliest possible phase in the product or system life cycle. Just as subsystems can fail with potentially disastrous effects, so can the individual hardware and components that make up those subsystems. As with the functional FMEA, the hardware FMEA evaluates the reliability of the system design. It attempts to identify single-point failures, as well as all other potential failures, within a system that could possibly result in failure of that system. Because the FMEA can accurately identify critical failure items within a system, it can also be useful in the development of the preliminary hazard analysis and the operating and support hazard analysis (Stephenson 1991). It should be noted that FMEA use in the development of the O SHA might be somewhat limited, depending on the system, because the FMEA does not typically consider the ergonomic element. Other possible disadvantages of the FMEA include its purposefiil omission of multiple-failure analysis within a system, as well as its failure to evaluate any operational interface. Also, in order to properly quantify the results, a FMEA requires consideration and evaluation of any known component failure rates and/or other similar data. These data often prove difficult to locate, obtain, and verify (Stephenson 1991). [Pg.114]

Software System Hazard Analysis This type of analysis is conducted similar to a hardware system hazard analysis (SHA), analyzing software functional processing steps to determine whether they may have any particular hazardous effect on the system. The analysis utilizes a hazard-risk index to illustrate the severity of each potential failure. The main advantage to this method is in its ability to positively identify safety-critical hardware and software functions as well as consider the effect of the human element in system software operations. The results of the software SHA, which identifies single-point failures or errors within a system, can often be used to assist in the development of a software fault tree analysis or, to some degree, a system FMEA. However, as with the other various SWHA techniques briefly described above, this method is also time-consuming and costly to perform. [Pg.181]

Failure Modes and Effects Analysis systems safety technique that analyzes systems individual components for the purpose of identifying single point hazards. [Pg.164]

Run a single-point energy calculation on methanol using the HF/6-31++G(d,p) model chemistry, including the GFPrint and GFinput keywords in the route section which request that the basis set information be included in the output file (in tabular and input format, respectively). Examine the basis set output and identify its main components. [Pg.107]

Genotoxicity studies are required to identify compounds that can induce genetic damage ranging from single point gene mutations to gross alterations of chromosomal structure. Such effects are taken as indicative of the potential to cause cancer or heritable defects in humans. A standard battery of three types of test is recommended ... [Pg.66]

These studies may also point out locations or items of equipment that are critical or single point failures for the entire facility. Where such points are identified special emphasis should be to ensure that events leading up to such circumstances are prevented or eliminated. [Pg.89]

Several catastrophic fire incidents in the petroleum industry have been the result of the facility firewater pumps being directly affected by the initial effects of the incident. The cause of these impacts has been mainly due to the siting of the fire pumps in vulnerable locations without adequate protection measures from the probable incident and the unavailability or provision of other backup water sources. A single point failure analysis of firewater distribution systems is an effective analysis that can be performed to identify where design deficiencies may exist. For all high risk locations, fire water supplies should be available from several remotely located sources that are totally independent of each and utility systems which are required for support. [Pg.99]

Any location that has a connection to the SCADA network is a target, especially unmanned or unguarded remote sites. Conduct a physical security survey and inventory access points at each facility that has a connection to the SCADA system. Identify and assess any source of information including remote telephone/ computer network/fiber optic cables that could be tapped radio and microwave links that are exploitable computer terminals that could be accessed and wireless local area network access points. Identify and eliminate single points of failure. The security of the site must be adequate to detect or prevent unauthorized access. Do not allow live network access points at remote, unguarded sites simply for convenience. [Pg.131]

In order to extend the approach to include deracemization of chiral secondary amines, this group carried out directed evolution on the monoamine oxidase (MAO) enzyme MAO-N (Scheme 2.32). A new variant was identified with improved catalytic properties towards a cyclic secondary amine 64, the substrate used in the evolution experiments. This new variant had a single point mutation, lle246Met, and was found to have improved catalytic properties towards a number of other cyclic secondary amines. The new variant was used in the deracemization of rac-64 yielding (R)-64 in high yield and enantiomeric excess [34]. [Pg.36]

For each noncUnical laboratory study, a scientist or other professional of appropriate education, training, and experience, or combination thereof, shall be identified as the study director. The study director has overall responsibility for the technical conduct of the study, as well as for the interpretation, analysis, documentation and reporting of results, and represents the single point of study control. The study director shall assure that... [Pg.59]


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See also in sourсe #XX -- [ Pg.40 , Pg.318 , Pg.319 ]




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