In fault tree analysis, which logic gate is used to indicate that all listed failures must occur to cause the top event?

In fault tree analysis, which logic gate is used to indicate that all listed failures must occur to cause the top event?

• A. NOT
• B. AND
• C. XOR
• D. OR

Answer: (B)

In fault tree analysis, the gate that represents that all listed failures must occur for the top event is the AND gate. It expresses a logical conjunction: the top event happens only when every input failure occurs. This captures situations where multiple faults must coincide to drive the system failure, so if even one input does not happen, the top event cannot occur. For context, fault trees use gates to combine basic events into higher-level events, showing how different faults interact. The NOT gate inverts a single input, the OR gate allows the top event to occur if any one input happens, and the XOR gate requires exactly one of the inputs to occur.

In fault tree analysis, the gate that represents that all listed failures must occur for the top event is the AND gate. It expresses a logical conjunction: the top event happens only when every input failure occurs. This captures situations where multiple faults must coincide to drive the system failure, so if even one input does not happen, the top event cannot occur. For context, fault trees use gates to combine basic events into higher-level events, showing how different faults interact. The NOT gate inverts a single input, the OR gate allows the top event to occur if any one input happens, and the XOR gate requires exactly one of the inputs to occur.