Severity three-dimensional numerical risk scoring

Some risk assessment systems include numerical categories for probability and severity levels and computations are made to arrive at a number that determines the risk level. Arriving at those numerical categories is entirely judgmental. Some of those numerical risk assessment systems are discussed in Chapter 10, Three-and Four-Dimensional Numerical Risk-Scoring Systems. ... 

For this primer, two-dimensional risk assessment matrices are discussed. They are displays of variations for two categories of terms the severity of harm or damage that could result from a hazards-related incident or exposure, and the probability that the incident or exposure could occur. They also show the risk levels that derive from the various combinations of severity and probability. A review of three- and four-dimensional risk assessment systems is given in Chapter 10, Three- and Four-Dimensional Numerical Risk-Scoring Systems. ... 

THREE AND FOUR DIMENSIONAL NUMERICAL RISK SCORING SYSTEMS TABLE 4 Suggested Design FMEA Severity Evaluation Criteria ... 

Although three- and four-dimensional risk scoring systems are now more commonly used, there are several reasons to be inquisitive and cautious concerning their content, the meanings of the terms used in them, the numerical values applied to the gradations within elements to be scored, and how they are applied in determining risk levels. 

In the process, for each identified hazard, numerical scorings as follows are given to Severity, Exposure, and Probability. It is significant that they are totaled to arrive at a final rating, not multiplied in sequence as is the case in other three- and four-dimensional risk-scoring systems. Thus, the status of the severity... 

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