Fault Tree Analysis(FTA) is a top-down, deductive failure analysis method used to determine the root causes of system failures. It is widely used in engineering, risk assessment, and reliability analysis to identify potential faults and improve system safety.

Key Components of a Fault Tree

1. Top Event – The undesired system failure or hazardous event being analyzed.
2. Intermediate Events – The contributing failures that lead to the top event.
3. Basic Events – The root causes or fundamental failures at the lowest level.
4. Gates – Logical symbols (AND, OR) that connect events and define how failures propagate.

Symbols Used in FTA

• AND Gate (•) – The top event occurs only if all input events occur.
• OR Gate (≥1) – The top event occurs if at least one of the input events occurs.
• Basic Event (○) – A fundamental failure that cannot be broken down further.
• Intermediate Event (□) – A fault resulting from lower-level failures.
• Transfer Symbol (⇒) – Used when parts of the fault tree are repeated elsewhere.

Process of Fault Tree Analysis

1. Define the Problem – Identify the system failure or hazard to analyze.
2. Construct the Fault Tree – Start with the top event and systematically break it down using logical gates.
3. Identify Basic Events – Determine root causes at the lowest level.
4. Quantify Failure Probabilities – Assign probabilities to events (if required) to analyze system reliability.
5. Evaluate & Mitigate Risks – Identify critical failure points and implement corrective measures.
   

Advantages of Fault Tree Analysis

1. Identifies root causes of failures.
   
2.  Helps in preventive maintenance planning.
   
3. Supports decision-making for risk reduction.
4.  Allows quantitative risk assessment.
   
5. Enhances system reliability and safety.