Which is the availability of a software with the following reliability figure?…
2022
Which is the availability of a software with the following reliability figure? Mean Time Between Failure (MTBF) = 25 days, Mean Time to Repair (MTTR) = 6 hours.
- A.
1%
- B.
9%
- C.
99.009%
- D.
99.09%
Attempted by 158 students.
Show answer & explanation
Correct answer: C
Solution:
Convert MTBF to hours: 25 days × 24 = 600 hours
MTTR is already in hours: 6 hours
Availability formula:
A = MTBF / (MTBF + MTTR)
Substitute values: A = 600 / (600 + 6) = 600 / 606
Decimal form: ≈ 0.990099
Percentage form: ≈ 99.009% (rounded to three decimal places)
Therefore, the availability is 99.009%.