Assessment of Risk as a Bi-Parametric Quantity e.g. MIL STD 882C

Risk assessment by means of immeasurable quantification is used if there is no clear interface between the individual elements of the Man-Machine-Environment system, and in the process of the assessment it is difficult to precisely determine the values of probability (frequency) and consequence of a negative event. This includes MIL STD 882C elaborated by the US Department of Defense and is quite frequently utilized mainly by small and medium-sized enterprises. 

The quantitative risk assessment is carried out on the basis of a matrix in which the relation between probability, consequence, and risk is clearly defined (see Table 4.3). 

The above-mentioned point-based method defines four levels of risk within the range of 1 to 20 points. Determining the risk levels allows for the introduction of particular measures to reduce risk. 

Probability/Consequence Catastrophic II Critical III Marginal IV Negligible 

The point-based method is frequently used in practice to assess risks of individual types of machines and machinery. Versatility of the method is limited by the fact that the division of the risks into probability and consequence groups is based on a subjective assessment, which thus calls for a high-quality assessor. 

---