F 社の経理部では，IT サービスを行っている G 社の会計システム（以下，新システムという）の導入を進めている。経理部では，新システムの稼働後は，G 社へ新システムの保守と運用を委託する予定にしており，新システムが引き渡された後のサポート内容について，G 社と詳細を詰めることにした。 保守，運用に関する G 社の基本サービスは，次のとおりである。 〔保守，運用に関する G 社の基本サービス〕 (a) 新システムについての問合せ対応は平日だけで，電子メールで受け付け，電子メールで回答を行う。 (b) 新システムで発生した障害の切分けと，発見されたバグの修正対応を行う。 (c) 新システム運用のサービス提供時間は，平日9:00～19:00とする。 (d) 新システムで障害が発生した場合は，発生時から9時間以内に復旧を行う。データのバックアップを日次で行い，1か月分のデータの保管を行う。ディスク障害が発生した場合は，前日までのデータの復旧を保障する。 一方，経理部は，新システムの利用及びサポートについて，G 社に対して次の要望をもっている。 〔新システムの利用及びサポートに関する要望〕 (1) 新システムの使用方法の問合せを平日9:00～18:00の間，電話と電子メールで対応してほしい。 (2) 新システムで障害が発生した場合に対応してほしい。 (3) 新システム稼働後も利便性向上のための新システムの修正を行ってほしい。 (4) 新システムの通常の利用は，平日の9:00～18:00としたい。 (5) 決算などの繁忙期は，夜間，休日なども新システムを利用できるようにして，問合せにも対応してほしい。 G社の基本サービスで, 保守・運用に関するサービスの内容を, 時刻や時間などを定量的に定義して適切に示しているものはどれか。
平成25年度 春期 ITパスポート試験 問91
This question's explanation and your answers so far.
問 91
※ Our check while writing this explanation could not fully confirm the published answer; scoring follows IPA's official key.
Incorrectア
(c) is indeed quantified with times of day, weekdays 9:00 to 19:00, but (a) is not quantitative. (a) says that inquiries are handled only on weekdays, received by e-mail and answered by e-mail, so it merely states the day-of-week category for handling (weekdays) and the means of receiving and answering (e-mail). It gives no numbers at all for from what time to what time inquiries are received, or within how many hours an answer is returned after receipt, so the degree of achievement cannot be measured. Therefore ア, which includes (a), is wrong.
Incorrectイ
(d) is quantified with numbers, recovery within 9 hours, daily backups, and one month's worth of data retained, so it is fine, but (a) is not quantitative. All that (a) shows is the days on which inquiries are handled and the means of contact; it lacks numbers for time of day or length of time, such as the time band for receiving inquiries or the time taken until an answer. Because (a) does not satisfy the question's condition of presenting the service content quantitatively, イ is wrong.
Incorrectウ
(c) is correct, but (b) is not quantitative. (b) says that failures occurring in the new system are isolated and pinned down and that the bugs found are fixed, so it only describes qualitatively how far Company G takes on the work, that is, the scope of the service. It contains no time figures at all, such as how many hours are spent on isolating a failure or within how many days a bug is fixed, so it cannot be said to define the content of the service quantitatively. Therefore ウ is wrong.
- エ
正解 The correct answer is エ, (c), (d). This question asks which of Company G's basic services (a) to (d) define the content of the service with numbers such as times of day and lengths of time, that is, define it quantitatively. A quantitative definition means stating something in a form that anyone who reads it can measure as the same value, in other words with numbers such as from what time to what time, within how many hours, how many times, or how many months' worth. (c) says that the service hours for operating the new system are weekdays 9:00 to 19:00, so it states the time band in which the service is provided by its start time and end time. (d) says that when a failure occurs, recovery is completed within 9 hours from the time it occurred, and that data is backed up daily and one month's worth of data is kept; it expresses the upper limit of the time until recovery, the frequency of backups, and the retention period of the data all as numbers. Both can be objectively measured as to whether they were achieved, and they are typical examples of the service levels written into an SLA (Service Level Agreement). Therefore the two that are quantitatively defined are (c) and (d), so エ is correct.
- Quantitative definition of service levels: in an SLA (Service Level Agreement) or an SLO, the content of a service is expressed with numbers such as times of day, lengths of time, frequencies, and periods, for example service hours of weekdays 9:00 to 19:00, recovery from a failure within 9 hours of its occurrence, and daily backups with one month's worth of data retained. Once it is expressed with numbers, both the provider and the user can measure and evaluate the degree of achievement by the same standard, which prevents mismatched understandings and endless arguments.
- Telling this apart from qualitative statements: statements such as handling inquiries only on weekdays, answering by e-mail, and isolating failures and fixing bugs indicate the scope of application and the means of carrying out the service. They are necessary agreements, but they are not quantitative service levels. In service level management, it is important to separate such statements of scope from measurable numerical targets.