Quantitative risk analysis dependence

Risk analysis is a term that is applied to a number of analytical techniques used to evaluate the level of hazardous occurrences. Technically, risk analysis is a tool by which the probability and consequences of incidents are evaluated for hazard implications. These techniques can be either qualitative or quantitative, depending on the level of examination required. 

It should be noted here that a choice of the risk assessment methodology (quantitative versus qualitative) depends on the nature of the risk being analysed and the needs of the safety analysis ... 

Risk Analysis (RA) is a fundamental process to prevent accidents and other unwanted events possibly occurring during industrial process activities handling of hazardous materials. It is defined as the process of systematic use of available information in order to identify hazards and to estimate the risk (lEC 60300 1995). Depending on the accuracy required to the analysis, it can be qualitatively or quantitatively carried out. In qualitative methods no explicit quantification of the risk is obtained, whereas in the quantitative ones a numerical calculation of the risk level is addressed. 

Depending on the requirement of the safety analysts and the safety data available, either a qualitative or a quantitative safety analysis can be carried out to study the risks of a system in terms of the occurrence probability of each hazard and possible consequences. As described in Chapter 3, qualitative safety analysis is used to locate possible hazards and to identify proper precautions (design changes, administrative policies, maintenance strategies, operational procedures, etc.) that will reduce the frequencies or/and consequences of such hazards. 

YuXetal (2006) A system-based approach to interpret dose- and time-dependent microarray data quantitative integration of gene ontology analysis for risk assessment. Toxicol Sci 92 560-577. doi kfjl84 (pii)10.1093/ toxsci/kfjl84... 

Sample preparation in NLC and NCE is the most important step in analysis due to the nano nature of these modalities. The sampling should be carried out in such a way as to avoid changes in the chemical composition of the sample. The quantitative values of species depend on the strategy adopted in sample preparation. Extraction recoveries may vary from one species to another and they should, consequently, be assessed independently for each compound as well as for the compounds together. Materials with an integral analyte, that is, bound to the matrix in the same way as the unknown, which is preferably labeled (radioactive labeling) would be necessary, which is called method validation. As discussed above few papers described off- and online sample preparation methods on microfluidic devices. Of course, online methods are superior due to lower risk of contamination and error of methods. Not much work been carried out on online nanosample preparation devices, which need more research. Briefly, to get maximum extraction of analytes, sample preparation should be handled very carefully. 

The magnitude of risk from some event depends on the product of how often the analyst thinks an event will occur and how seriously the event impacts on the overall process. Therefore, it is. incumbent on the scientist to develop a quantitative sense of where the risks in an analysis exist, and how serious they are. The best systems analyst cannot perform this function only the person who the is most knowledgeable about the analytical procedure can function as the risk assessor. This person is normally the research chemist who developed the methodology and not the analyst who may run the procedure routinely. He or she is most familiar with the emerging methodology and has a basis (whether it be historical, intuitive or reasoned) to assign a factor of risk to the individual components of the analysis. Typical mechanisms for risk assessment studies include either the use of a "Fault Tree", which uses lists of major failures and associated minor failures which might cause them, or a "Failure Modes and Effects Analysis Model" (21) which uses lists of the ways a system can fail and the results of each failure. For this study, the "Failure Modes and Effects Analysis Model" was chosen. 

Several methods relating to hazards analysis and risk assessment exist. They are generally divided into qualitative and quantitative (lEC 61508 lEC 61511). The choice of specific method depends on accident scenario being considered and available data. When a risk evaluated for scenario considered is high, it is necessary to reduce it to an acceptable level using protection layers, each of specified reliability, expressed often as the probability of failure on demand (PFD) (LOPA 2001). 

AS/NZS 4360 discusses different types of analysis, ranging from purely qualitative to purely quantitative ones. According to the Standard, the selection of the type of analysis should, amongst other, depend on the availability of numerical data and the proportionality of the time and effort needed for a fuller assessment. Unlike the AS/NZA 4360, Basel II is explicit about its preference for quantitative methods (for computing VaR). This difference can be attributed to the characteristics of the (financial) risks covered by Basel II while Basel II only deals with the financial sector, the AS/NZA 4360 Standard is supposed to fit a wide range of firms and industries. 

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