Decision Table Method

The hazard identification methods presented in Sections 1.5.1 to 1.5.6 above are all based on strongly systematic procedures. In the check list method, the systematic is provided by the check list itself. The comprehensiveness can be verified in the matrix (see Figures 1.4 and 1.5). With the FMEA, the systematic is provided by the division of the system into elements and the failure modes considered. In the HAZOP study, the systematic stems from the division of the plant into nodes and lines, then the systematic application of the keywords. With the decision table method, the systematic is inherent to the table. For the FTA and ETA, the systematic is given by the tree and the logical ports. Nevertheless, the work of the team must be traceable, even by persons who did not participate to the analysis. Thus, it is recommended to also document the hazards that were not considered as critical. 

Inductive methods, such as check lists, Failure Mode and Effect Analysis (FMEA), event trees, decision tables, Analysis of Potential Problems (APP). These methods proceed from an initial cause of the deviation and construct a scenario ending with the final event. They are based on questions of the type What if ... 

The top five suppliers identified by the aforementioned group decision-making methods are presented in Table 7.19. 

An important review of criteria and anal5d ical methods in the area of domestic supplier selection has been done by Weber et al. (1991), who reviewed 74 articles that discuss supplier selection. Further, they provide a comprehensive list of the criteria that academicians and purchasing practitioners have considered as important in the supplier selection decision (Table 8.3). It is interesting to note that most articles consider more than one criterion when developing supplier selection models, emphasizing the inherent multiobjective nature of the supplier selection process. 

Computer-aided automation of process design requires a whole new approach to part manufacture and assembly planning. This centres on the decision logics, formulae, algorithms and data extractions. This approach is labelled as the Generative Method [4]. Examples of such procedures are Decision Trees, Decision Tables, Axiomatic and Expert systems. Regardless of their approach they remain complex in nature and this led to the specific applications, such as those in sheet metal fabrications and electronics manufacture, where parameters are more... 

Safety analysis uses logic structure representative of possible incidents. Such work methods as fault tree, incident analysis, and decision table are suitable for this purpose. Computation rules for determination of expected frequency of incidents must be formulated accordingly. In a broad sense all mathematical simulation methods which are suited for determination of stress states in technical installations and their parts become aids in safety analysis. These will be described in partial detail later. Here characteristic work methods which are of direct significance with respect to system-related and prognostic consideration of safety analysis will be discussed first,... 

Decision Table Technique. Fault tree analysis and incident sequence analysis are methods leading to the representation of the logic structure of... 

In this chapter, we looked at six of the most commonly used solvent-based CO2 capture solvents apphed to eight different applications, as well as methods for constructing detailed models in four of the most popular commercial chemical process simulation software packages. In general, CO2 capture modelling is tricky, particularly when it comes to absorption. Each program has its own tricks and nuances which, once learned, make CO2 capture simulations much more tractable. A summary of the apphcations studied is shown in Figure 7. Note that each process may have different characteristics and so other solvents or solvents not marked in the table could potentially be better. However, the purpose of this chapter is to equip the reader with the tools necessary to make those decisions (Table 5). 

Risk Analysis Another group of methods used in system safety involve risk analysis. In many cases, the hazards are charted into a risk decision table or risk assessment matrix (see Figure 6.5). The severity of hazards is rated and charted on one axis of the chart. The probability of occurrence is on the other axis. Then severity-probability cells are marked for the kind of action required, such as risk reduction required, management approval, or that the operation is permissible. 

The calculation method can be selected by application of the decision tree in Figure 9.2. The liquid temperature is believed to be about 339 K, which is the temperature equivalent to the relief valve set pressure. The superheat limit temperatures of propane and butane, the constituents of LPG, can be found in Table 6.1. For propane, T, = 326 K, and for butane, T i = 377 K. The figure specifies that, if the liquid is above its critical superheat limit temperature, the explosively flashing liquid method must be chosen. However, because the temperature of the LPG is below the superheat limit temperature (T i) for butane and above it for propane, it is uncertain whether the liquid will flash. Therefore, the calculation will first be performed with the inclusion of vapor energy only, then with the combined energy of vapor and liquid. 

Table 7.1.1 summarizes CQP concept principles and also cites typical tools, methods, and concepts that can be used to support decision making for each principle. We do not explain the techniques in detail, but we have included dedicated references explaining the principles and mechanisms. Some are highlighted below. 

The selection of optimum inspection methods and frequencies for high temperature hydrogen attack in specific equipment or applications is the responsibility of the user. The information below and in Tables D-1 and D-2 are intended to assist the user in making such decisions. 

Another way is by the confidence required by the customer or other users of the results. This applies to both qualitative and quantitative methods. It hinges on the consequences of making a wrong decision. In some cases, the consequences may be modest and then the degree of confidence in each result can be lower than where there are serious consequences if wrong decisions are made. Some of the terms used to indicate the degree of confidence offered by an analytical method are listed in Table 4.1. 

Table 3 describes the main parts of an environmental risk assessment (ERA) that are based on the two major elements characterisation of exposure and characterisation of effects [27, 51]. ERA uses a combination of exposure and effects data as a basis for assessing the likelihood and severity of adverse effects (risks) and feeds this into the decision-making process for managing risks. The process of assessing risk ranges from the simple calculation of hazard ratios to complex utilisation of probabilistic methods based on models and/or measured data sets. Setting of thresholds such as EQS and quality norms (QN) [27] relies primarily on... 

Only a small subset of method-specific questions are shown in Table 2.3 because of the breadth of chemometric and measurement methodology. Understanding the information in Chapters 3-5 will help generate chemometric-related questions. The decision trees in these chapters can also help determine appropriate method(s) for a given situation. In time, your experience will also become a valuable resource. 

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