RAM Performance Optimization & Availability 2

Question 1

Which metric best quantifies the proportion of time a system is operational and available for use?

Accepted Answer

Operational Availability (Ao)

Answer

Operational Availability (Ao) is the ratio of uptime to total calendar time, directly expressing what fraction of time a system is available for its intended function.

Question 2

A system has an MTBF of 500 hours and an MTTR of 50 hours. What is its inherent availability?

Accepted Answer

0.909

Answer

Inherent Availability = MTBF / (MTBF + MTTR) = 500 / (500 + 50) = 500/550 ≈ 0.909.

Question 3

What is the primary purpose of 'availability allocation' in system design?

Accepted Answer

Assigning availability targets to subsystems so the overall system availability requirement is met

Answer

Availability allocation distributes the top-level availability requirement down to subsystem and component levels to ensure the overall system goal is achievable.

Question 4

In RAM analysis, 'achieved availability' differs from 'inherent availability' primarily because it includes:

Accepted Answer

Both scheduled preventive and unscheduled corrective maintenance downtime

Answer

Achieved Availability (Aa) accounts for both scheduled (preventive) and unscheduled (corrective) maintenance downtime, whereas Inherent Availability excludes preventive maintenance.

Question 5

Which design strategy improves availability by reducing the time required to perform corrective maintenance?

Accepted Answer

Improving testability and accessibility (Design for Maintainability)

Answer

Design for Maintainability reduces MTTR by improving fault isolation, access, and repair procedures, directly increasing availability.

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

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

RAM Performance Optimization & Availability 2