Hazards risk decision table

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 proposed systems framework for EU decision-making under REACH seeks to counterbalance the weaknesses and to draw on the strengths of the national approaches while addressing the points shown in Table 7.1. Specifically, the framework would fuse hazard, technical and risk-benefit approaches to risk management (Table 7.2). Compared with the current process of chemical legislation and the recent REACH proposal, the systems framework would avoid a linear substance-by-substance approach by applying a set of decision-making rules based on hazard and use to all chemicals (Section 5.3.1). 

Earlier in this chapter, reference was made to a speaker who reviewed the hazard analysis and risk assessment methods used in his company, which relied on typical risk assessment and decision-making matrices, to achieve acceptable risk levels. Use of such matrices is a method some organizations apply to arrive at acceptable risk levels. Table 15.1 is an example of such a risk assessment matrix. Using the results from Table 15.1, levels of remedial action or risk acceptance for individual risk categories can be established, as in Table 15.2. 

Table 14.5 uses the hazard risk index from the previous table and develops what NASA calls a launch commit criterion. This is the actual decision of whether they wish to launch or not. 

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... 

Of course, the sponsor faces a game of heads you win, tails I lose. It is conceivable that the results could be the other way around. Consider Table 15.2. Now StatXact (R) produces a lower confidence interval of 0.7064 and nowhere near the value of 0.75 requested. However, the control group rate is 0.9 and, for this rate, the odds ratio of 0.7064 produces a risk difference of 0.027. Similar situations arise with survival analysis where one may be interested regarding decision making in the difference in median or mean survival but the analysis delivers a hazard ratio. 

Then one uses the risk score to decide how quickly to act to correct the hazard. See Table 34-7 for decision guidance. One can compute a cost justification value, 7, from... 

In that text, the discussion of each step is extensive. Comments will be made here on the first two only. The remaining steps are addressed in Chapter 12, Hierarchy of Controls The Safety Decision Hierarchy. For Step 1,—Identify the hazards—the hazard analysis and risk assessment methodologies are as shown in Table 2. 

Table 8 Is based on HSE s Guidance on ALARP decisions in control of major accident hazards (COMAH) SPC/Permissioning/12. Note that a scenario-based risk assessment with a single fatality is not the same as an Individual Risk calculation. 

The 19 concepts that were presented on the Tables 1 and 2 (three of these concepts are included in the 1st, 2nd and 4th macro procedures to be presented in the discussion) are (i) Ergonomics-based design (ii) Leadership commitment (iii) Employee involvement in decision making (iv) Risk assessment and communication (v) Events reporting and investigation (vi) Job Hazard Analysis (JHA) (vii) Health problem management ... 

The outcomes of the hazards analyses and risk assessment are the basis for a company s management in a decision-making process of selecting effective methods and procedures to reduce risk. Both lifting machine manufacturers and users may contribute to risk reduction (see Table 4.5). 

To determine the disruption risk of facilities and transportation links, a decision maker first rates each attribute on a three-point scale (1, 2, 3 the higher number indicates the higher level for disruption risk). The description of disruption risk factors and their attributes for a facility and a transportation link are given in Table 7.1. The guidelines for attribute rating are provided in Table 7.2. Once the attributes are rated, the hazard score. 

Regardless of incentives and information, travelers must be sufficiently competent to make good decisions. The belief that individuals are incompetent to make risky decisions arises from research on behavioral decision rules in complex situations and on attitudes. Traffic safety dedsions are suspect because risks may be misperceived and expected safety benefits may be undervalued. Ola Svenson and his colleagues, for example, report based on their attitudinal study that subjects show optimism bias they feel they are more skillful and safer than typical drivers. They state that drivers who feel immune may discount measures such as seat belts. A sununary of this and other representative evidence of representative incompetence is presented in column 2 of Table 2-1. Next to these results, in column 3, is the evidence of competence for each subject natural hazards and insurance, gambling, risk perception, and safety belt use. 

---