Societal Risk Assessed in Terms of an FN Diagram
FN diagrams are used to present information regarding risks. They can be used to represent three vital types of information, namely: historical incidents record, quantitative risk analysis results, and judging criteria for risk tolerability. Two key variables are important in estimated risk analysis. These include the forecasted event occurrence frequency and forecast number of persons suffering a fatality.
Construction of FN diagrams involves listing all possible vents and their respectively expected frequencies as well as consequences. These are compiled and sorted out in decreasing the number of consequences. In plotting, the event frequencies are translated into cumulative frequencies. Mathematically, the curve criterion used in F-N diagrams is represented as shown below:
F x N a = k, and hence F = k x N-a.
Where F is the cumulative frequency and N represents the number of fatalities suffered. A is the aversion factor which often ranges between 1 and 2. K is a constant. The curve’s slope equals – a when plotted on a log-log basis and is representative of aversion degree concerning multi-fatality event occurrence embodied in the methodology. In FN diagrams, high slopes symbolize the fact that stringent risk control measures are applied in the reduction of risk within regions where risk confidence estimate has a low likelihood. This is a region where the cumulative risk is characterized by remote events and not small event combinations. They help in the aversion of multiple fatality risks as they recognize that significant fatality areas are those areas where the fatality numbers registered are high.
FN diagrams are useful tools in the mining industry. They not only act as analytical tools but also offer an insightful understanding of the risk factors that cause most fatal events within the mines. High-risk areas are identified, and measures to alleviate their effect are taken into consideration. Mines suffer increased fatalities within their operations, and there are plenty risky prone areas. An efficient tool for sieving these risks is necessary. This gap is filled with FN diagrams, which diligently assist in classifying risk areas that result in more fatalities. These areas can therefore be accorded the care it demands.