Fault Tree Analysis

Correct Answer: Markov Chain Analysis to model state transitions and dependencies

Markov Chain Analysis is the most appropriate method for handling non-independent basic events in Fault Tree Analysis (FTA) for several key reasons: Markov Chain Analysis can: - Model complex dependencies between events and system states - Account for time-dependent transitions between states - Capture conditional probabilities and interdependencies - Represent dynamic system behavior Other approaches are inadequate because: Simple multiplication of probabilities assumes events are independent, which contradicts the premise of the question. Addition using Boolean algebra does not account for dependencies and can lead to incorrect probability calculations when events are related. Sequential bottom-up calculation alone cannot properly address the interdependencies between events and may result in inaccurate system failure predictions.

Correct Answer: Using an inhibit gate with conditional probability

In Fault Tree Analysis (FTA), mutually exclusive events are best represented using an inhibit gate with conditional probability. This is the correct approach because: 1. Mutually exclusive events cannot occur simultaneously by definition 2. Inhibit gates allow for the incorporation of conditional dependencies 3. The conditional probability factor accurately represents the relationship between exclusive events 4. This approach maintains the logical integrity of the fault tree structure The other options are incorrect because: - Using multiple OR gates would suggest events could potentially occur together, which contradicts mutual exclusivity - XOR gates with sequential timing parameters add unnecessary complexity and may not accurately represent the probabilistic nature of the events - Nested AND gates would suggest all events need to occur together, which is the opposite of mutual exclusivity The inhibit gate solution provides the clearest and most accurate representation of mutually exclusive events in FTA, ensuring proper probability calculations and risk assessment.

Correct Answer: It starts with a major failure event and breaks down into basic contributing causes

Fault Tree Analysis (FTA) is a deductive reasoning method that follows a top-down approach. The correct answer accurately describes the FTA process: starting with a major failure event (called the top event) and systematically breaking it down into basic contributing causes using logic gates and events. The other options are incorrect because: - Starting with individual components and building up describes a bottom-up approach, which is characteristic of FMEA (Failure Mode and Effects Analysis), not FTA - Analyzing successful conditions and extrapolating deviations describes a different analysis method (closer to deviation analysis) - Starting with risk probability calculations is incorrect as FTA begins with identifying the undesired event first, before any probability calculations are performed.