Step 5 - Decision-making

The final step is the decision-making phase, which aims at making decisions and giving recommendations for safety improvement. At this point, the various stakeholders interest in the vessel under study is considered. The cost and benefit applicable to each stakeholder have to be determined in order to decide the best risk control option - each RCO will have a different 

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Monitoring drug therapy In a systematic review of the use of plasma ribavirin concentrations to monitor therapy in patients with chronic hepatitis C (30 studies), a previously published nine-step decision-making algorithm was used to help determine whether measurement is warranted [50 ]. Some studies have supported and others have refuted the usefulness of ribavirin measurement most had methodological limitations, such as small sample size, retrospective analyses, and lack of P value adjustment for multiple analyses. 

In an effort to identify problems in the design and performance of SRBs, engineers in the SRB Work Group used a Five-Step Decision Making Sequence ... 

In response to new signals of potential danger, the five-step decision-making process was repeated. Each time, evidence of joint performance initially interpreted as a deviation from expected performance was interpreted as within the bounds of acceptable risk. The Work Group had, in a problem-driven, incremental fashion, developed a three-factor technical rationale to normalize deviance and deem a risk as an acceptable risk, consisting of... 

Decision Process. In many cases, the decision regarding the need for exposure reduction measures is obvious and no formal statistical procedure is necessary. However, as exposure criteria are lowered, and control becomes more difficult, close calls become more common, and a logical decision-making process is needed. A typical process is shown in Eigure 2. Even when decision making is easy it is useful to remember the process and the assumptions involved. Based on an evaluation, decisions are made regarding control. The evaluation and decision steps caimot be separated because the conduct of the evaluation, the strategy, measurement method, and data collection are all a part of the decision process. 

Step f considers all of the background information discussed in Section 2.f. If the information requirement is based on a regulatory concern or a special purpose need, then Steps 2 through 5 are bypassed and a QRA should be performed. If the information is needed for decision making, you must determine whether the significance of the decision warrants the expense of a QRA. If not, you may be able to use less resource-intensive qualitative approaches to satisfy your information requirements. Table 8 contains examples of typical conclusions reached from qualitative risk analysis results. 

Many sophisticated models and correlations have been developed for consequence analysis. Millions of dollars have been spent researching the effects of exposure to toxic materials on the health of animals the effects are extrapolated to predict effects on human health. A considerable empirical database exists on the effects of fires and explosions on structures and equipment. And large, sophisticated experiments are sometimes performed to validate computer algorithms for predicting the atmospheric dispersion of toxic materials. All of these resources can be used to help predict the consequences of accidents. But, you should only perform those consequence analysis steps needed to provide the information required for decision making. 

Decision trees are not used in this book since they are most useful when targeted to a specific process attempts to generate comprehensive matrices rapidly lead to extremely complex schemes. Instead, the book should be used to help generate suitable matrices or to supplement the decision-making steps in published matrices such as [ 199 ]. Many of the decision steps, such as the conditions under which discharges of some specified effective energy may occur, are not properly understood and continue to be controversial. 

The Operator Action Tree (OAT) is a time reliability correlation method (NUREG/ CR-3010). specifically designed to estimate HEPs for actions requiring decision making on the part of the plant operator. It employs two steps (1) the development of an operator action tree which reflects the specific actions that may be taken by an operator faced with a particular decision, and (2) a time... 

Rules are provided to aid decision making at each step. The procedure is illustrated with examples including separation of amino acids, p- and / -cresols, chorobenzoic acids, calcium carbonate and magnesium oxide from dolomite, and the production of salt. 

The third step is to proceed to the component level because more than likely, the cause will be uncovered here. Table 62.2 shows machinery component failure modes commonly encountered in machinery failure analysis together with suggested standard life values, Weibull indices (/J), and responsiveness to preventable or predictable maintenance strategies. Referring to this table will help decision-making. To assist the analyst in documenting bad actor failure modes on the component level. 

The first step to define data requirements and criteria for decision making for residue analytical methods was attempted in Council Directive 94/43/EC, establishing... 

It is most important that the whole life cycle of a process plant can be evaluated on safety. Safety and risk analyses evaluate the probability of a risk to appear, and the decisions of necessary preventative actions are made after results of an analysis. The aim of the risk estimation is to support the decision making on plant localization, alternative processes and plant layout. Suokas and Kakko (1993) have introduced steps of a safety and risk analysis in Figure 2. The safety and risk analysis can be done on several levels. The level on which the analysis is stopped depends on the complexity of the object for analysis and the risk potential. 

Data are still generally typed into a database rather than electronically loaded from other systems. The first step of any data entry process should involve a check for duplicate cases. The need for decision making at the data entry stage will depend upon the type of database design. In all cases, there should be clear rules on how data should be entered into each field to ensure consistency and aid subsequent searching and outputting. This is particularly important when there are multiple users distributed over a number of international sites. Use of electronically available field specific lists of value and well-defined coding conventions will help with this. 

Three educational examples ("cases 1 - 3 ) were selected in order to simplify the presentation, clarify the essential steps needed for the evaluation and assessment of a reaction and the decision-making process concerning the type and extent of the necessary measures. The three educational examples are characterized by the following constraints ... 

The assumptions can be based on previous data or on the results of any available current analysis. What constitutes an appropriate model depends on the mechanism of the drug s action, the assumptions made, and the intended use of the model in decision-making. If the assumptions do not lead to a mechanistic model, an empirical model can be selected, in which case, validating the model s predictability becomes especially important. (Note that nonmechanistic models do not get good reviews from the FDA.) The model-selection process comprises a series of trial-and-error steps, in which different model structures or newly added or dropped components to an existing model can be assessed by visual inspection and can be tested using one of several objective criteria. New assumptions can be added when emerging data justifies it. 

Finally, the last step is the decision making process which is supported by the results provided by the combination rules. Indeed, as previously highlighted, the combination of the available sources of information provides us with a new belief function which represents the most reliable and complete information. However, if the choice of the most likely h3rpothesis is straightforward in the probabilistic framework, it can become quite complex in the Evidence theory. 

Phase 1 Outlining and assessing possible synthetic routes on paper. Here, the decision is made whether to use chemocatalytic steps for making the desired product or to use classical organic synthesis. This decision will depend on a number of considerations, such as the goal of the development, the knowhow of the investigators, the time frame, or the available manpower and equipment... 

This optional attachment provides a visual way to view the flow of the major steps and decision-making points of an incident investigation. It can be a helpful overview for management. 

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