RAM System Reliability Analysis 3

Question 1

A system has an MTBF of 500 hours and an MTTR of 10 hours. What is its steady-state availability?

Accepted Answer

0.980

Answer

Steady-state availability = MTBF / (MTBF + MTTR) = 500 / (500 + 10) = 500 / 510 ≈ 0.980.

Question 2

What is the 'bathtub curve' in reliability engineering used to describe?

Accepted Answer

The variation in failure rate over a product's lifetime

Answer

The bathtub curve illustrates how failure rate changes over a product's life: decreasing during infant mortality, constant during useful life, and increasing during wear-out.

Question 3

Which redundancy strategy activates the backup component only when the primary component fails?

Accepted Answer

Standby (cold) redundancy

Answer

Cold (standby) redundancy keeps the backup in a non-powered, non-operating state until the primary fails, at which point a switch activates the backup.

Question 4

In reliability-centered maintenance (RCM), what is the primary criterion for selecting a maintenance task?

Accepted Answer

The task must be cost-effective and technically feasible for addressing the failure mode

Answer

RCM selects maintenance tasks based on two criteria: the task must be technically feasible (capable of preventing the failure) and worth doing (cost-effective).

Question 5

What does the Risk Priority Number (RPN) in FMEA represent?

Accepted Answer

The product of Severity, Occurrence, and Detection ratings

Answer

RPN = Severity × Occurrence × Detection, and is used to prioritize which failure modes require corrective action in FMEA.

(RAM) Reliability, Availability, and Maintainability Certified Professional Practice Test

(RAM) Reliability, Availability, and Maintainability Certified Professional Practice Test

RAM System Reliability Analysis 3