Fault Tree Analysis
Fault Tree Analysis (FTA) is a systematic method of identifying and analyzing the causes of a particular failure. It is often used by system engineers, safety engineers, and project personnel to analyze potential safety issues and to measure the probability of a system failure or event that could lead to risk of injury or damage to property. The process involves creating a graphical model of the event or system and representing it with symbols, diagrams, and logic equations.
FTA follows a structured sequence of steps which includes the identification of the event being studied, the formation of a tree (or sequence) of events that could lead to the event, and an analysis of the potential hurdles to each event. Once these steps are completed, the model can then be further analyzed to identify potential solutions to reduce the likelihood of the event occurring.
The most common approach to FTA is to start off with a description of the event being studied. It is important to consider all of the elements that could be involved in the incident, as well as any external factors that could have an impact. Once the event has been identified, a tree can be created to map all of the possible causal factors that could contribute to the event occurring.
Using the tree, each element of the event is broken down into individual elements and linked with logic equations that represent the relationship between each of the components. For example, if one factor is identified as the cause of the event then this can be represented in a diagram using a ‘root cause’ box. Through this process, the model of the event is built up and the potential hurdles can be identified and evaluated.
The evaluation of the potential hurdles will allow for the estimation of a risk level for the event. This is done by assigning a probability value to each potential hurdle or ‘gate’ in the tree. The probability value is based on the probability that the event will occur if the gate is present or not present.
Once the evaluation has been completed, solutions to reduce the risk of the event occurring can be proposed. This is done by reducing the probability of the gates in the tree, so that the event is less likely to occur. In some cases, the solutions may involve implementing new safety measures in the workplace, such as the introduction of additional safety training or the introduction of safety equipment.
FTA is a powerful tool that can be used by project managers and engineers to identify potential hazards and to assess the likelihood of an event actually occurring. It can provide insight into the system and it can highlight areas of improvement that may need to be made to reduce the risk of the incident taking place. By understanding the various factors that could contribute to a particular event, solutions can be identified that will reduce the risk of the incident occurring and create a safer working environment overall.
