Equipment Reliability Flashcards

In a Failure Mode and Effects Analysis (FMEA), the Risk Priority Number (RPN) is calculated by multiplying which three factors?

Answer: Severity, Occurrence, Detection

RPN = Severity × Occurrence × Detection, and higher RPN values indicate higher priority failure modes for corrective action.

Which root cause analysis technique uses a diagram resembling a fish skeleton to organize potential causes of a failure?

Answer: Ishikawa diagram

The Ishikawa (fishbone) diagram organizes potential causes into major categories branching from the effect, resembling a fish skeleton.

A bearing fails prematurely showing spalling on one race. What failure mechanism is most likely responsible?

Answer: Fatigue

Spalling (surface pitting and material breakaway) on bearing races is a classic sign of rolling contact fatigue.

Which failure analysis method uses Boolean logic to evaluate combinations of component failures that lead to a top-level system failure?

Answer: Fault Tree Analysis

Fault Tree Analysis uses AND/OR logic gates to graphically map how combinations of lower-level failures cause a specific top-level undesired event.

When performing a '5-Why' analysis on a gearbox failure, the primary purpose is to:

Answer: Identify the physical, human, and latent root causes

The 5-Why method drills down through successive 'why' questions to uncover physical, human, and latent systemic root causes.

A shaft seal fails due to excessive radial load causing misalignment. According to RCA classification, this is best categorized as which type of root cause?

Answer: Physical root cause

The physical root cause is the tangible, material condition (excessive radial load causing misalignment) that directly produced the failure.

Which FMEA type is performed during the design phase to identify potential failure modes before equipment is manufactured?

Answer: Design FMEA

Design FMEA (DFMEA) is conducted during product design to identify and mitigate failure modes before manufacturing begins.