CRL Failure Analysis and RCA 2

Question 1

A shaft fracture surface shows smooth, curved beach marks radiating from a keyway corner with a small rough final-fracture zone. What failure mechanism is most likely?

Accepted Answer

High-cycle fatigue with low nominal stress

Answer

Beach marks from a stress concentrator with a small final fast-fracture zone indicate fatigue under relatively low nominal stress.

Question 2

In RCA terminology, which category of root cause addresses why an organization's systems allowed a human error to occur?

Accepted Answer

Latent (organizational) root cause

Answer

Latent roots are the management systems, procedures, and culture that allowed the physical and human causes to happen.

Question 3

Which piece of evidence is most perishable and should be collected first after a failure event?

Accepted Answer

Positions of components, debris, and witness recollections

Answer

Physical positions and people's memories degrade quickly, so they must be preserved before cleanup or repairs.

Question 4

A team keeps replacing a failed pump bearing every few months without asking why it fails. This practice is best described as:

Accepted Answer

Treating symptoms rather than root causes

Answer

Repeatedly replacing parts without addressing the cause treats the symptom and guarantees recurrence.

Question 5

What is the main advantage of a logic tree (cause-and-effect tree) over a simple 5 Whys analysis?

Accepted Answer

It captures multiple parallel causes and requires each hypothesis to be verified

Answer

Logic trees branch to show multiple contributing causes and require verification of every hypothesis.

CRL - Certified Reliability Leader Practice Test

CRL - Certified Reliability Leader Practice Test

CRL Failure Analysis and RCA 2