The main purpose of the fault tree analysis (FTA) is to help identify potential causes of system failures before the failures actually occur.
It can also be used to evaluate the probability of the top event using analytical or statistical methods.
These calculations involve system quantitative reliability and maintainability information, such as failure probability, failure rate and repair rate. After completing an FTA, organizations can focus efforts on improving system safety and reliability.
Organizations normally apply a Fault Tree Analysis when there is a new design with new content, or when a hazard analysis previously indicated a safety concern.
Fault Tree Analysis can also be used by organizations that have a current design with modifications, which may include changes due to past failure – or when there is a current design being used in a new environment or change in duty cycle and no physical change made to the design.
An important benefit of FTA is how the analysis provides a unique insight into the operation and potential failure of a system.
This allows the development team to explore ways to eliminate or minimize the occurrence of product failure. By exploring the ways a failure mode can occur by exploring the individual failure causes and mechanisms, the changes impact the root cause of the potential failures.
Analysts contend that a key step to successfully completing fault tree analysis is defining the system. This includes the scope of the analysis such as defining what is considered a failure. This becomes important when a system may have an element fail or a single function fails and the remainder of the system still operates.
Another key step is to identify the causes for top-level fault. By using logic gate symbols, team leaders can organize the causes that are responsible for the failure alone or the causes that require multiple events to occur before the failure occurs.
Want to learn more? Tonex offers Fault Tree Analysis Training, a 2-day course that teaches participants how fault tree analysis (FTA) is used in system engineering and analysis practices such as reliability, maintainability and safety.
FTA is a common method for safety assessments and probabilistic risk assessments (PRAs). A PRA is a systematic approach to risk and reliability analysis, which estimates risk, the likelihood of failure, and the magnitude of the consequences.
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