IPA IP 2024 Question 38
A question IPA Japan published in 令和6年度 ITパスポート試験 公開問題 問38, translated into English. ITPEC is based on the same exams.
In the operation of a system, an SLA was concluded with the users, and it was agreed that the available days are Monday through Friday, the available hours in a day are from 7:00 to 22:00, and the availability is 98% or more. In one (1) week of operation, what is the maximum number of hours for which a stop of the system due to failures, etc. can be allowed?
Explanation
1.5 hours — the 2% of agreed service time that may be lost, taken over the 5 service days of one week.
Availability in an SLA is measured over the agreed service time only, not over all 24 hours of all 7 days.
- •Service hours per day: 7:00 to 22:00 = 15 hours
- •Service hours per week: 15 × 5 = 75 hours (Monday through Friday)
- •Allowed stop: at least 98% available means up to 2% unavailable, 75 × 0.02 = 1.5 hours
Answer (b)
Why not others:
- •(a) 0.3 — 2% of a single day's 15 hours, not of the week
- •(c) 1.8 — 2% of 90 hours, six service days instead of five
- •(d) 2.1 — 2% of 105 hours, counting all seven days of the week
Key rule: Allowed downtime = agreed service time × (1 − availability); count only the days and hours the SLA covers.
Service Management · AI-written, may contain errors
This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.