IPA IP 2023 Question 46
A question IPA Japan published in 令和5年度 ITパスポート試験 公開問題 問46, translated into English. ITPEC is based on the same exams.
Indicators concerning IT services include MTBSI (Mean Time Between Service Incidents), which is the mean time between occurrences of incidents that make an IT service unavailable, and it represents how unlikely service interruptions are to occur. Which of the following is the most appropriate example of improving the MTBSI in an IT service?
Explanation
Duplicate the network to reduce connection failures — MTBSI grows only when incidents that stop the service happen less often.
MTBSI is the average time from one service-stopping incident to the next, so a longer MTBSI means fewer interruptions. It improves when failures are prevented or no longer stop the service. With a duplicated (redundant) network, the failure of one line or device is taken over by the other, so the service is not interrupted and such incidents become rarer.
Answer (c)
Why not others:
- •(a) — finding the cause faster shortens the time to diagnose and restore the service after an interruption (it improves MTRS, the mean time to restore service), not how often interruptions occur
- •(b) — more menus and users is a business goal; it does nothing to make incidents rarer
- •(d) — shorter waits at the help desk improve responsiveness to inquiries, not the interval between service incidents
Key rule: Interval measures (MTBSI, MTBF) improve by preventing failures, for example through redundancy; repair measures (MTRS, MTTR) improve by recovering faster.
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.