問33
頻出度★★☆
現在5分程度掛かっている顧客検索を，次期システムでは1分以下で完了するようにしたい。この目標を設定する適切な工程はどれか。
平成23年度 秋期 ITパスポート試験 問33
ストラテジ系システム企画 › 要件定義
This question's explanation and your answers so far.
解説
問 33
Incorrectア
System design is the process that works out how to realize the goals fixed in requirements definition. Examining indexes, database structure, and hardware configuration in order to achieve the within-1-minute goal is the role of design; it is not the process where the target value itself is newly set.
Incorrectイ
System testing is the process that verifies whether the completed system meets the requirements. It is where you actually measure whether the search finishes within 1 minute and judge pass or fail, so the goal used as the criterion must already have been fixed earlier, in requirements definition. If the goal were set during the testing process, there would be no basis for deciding pass or fail.
- ウ
正解 The correct answer is “ウ System requirements definition”. Completing a customer search within 1 minute is a performance (response time) goal that the next system must meet; it is not a function itself but a condition about quality and performance, so it is a non-functional requirement. Requirements define what the system should achieve and at what level, and the process that clarifies this as a demand from the user side and documents it as a measurable numeric target (within 1 minute) is the system requirements definition process. Once the goal is fixed here, the later design can choose methods that satisfy it (index design, server configuration, and so on), and testing can verify whether it was achieved. The key point is the order: the goal comes first, and the means of realizing it and the verification come afterward.
Incorrectエ
Software acceptance is the final process in which the client inspects the delivered system, confirms that it matches the requirements, and approves it for use in business operations. Here too the goal is only used as the criterion for confirmation. Setting a new performance target at the last stage of development would cause large rework, and it is also wrong in terms of the role of this process.
ここがポイント
- Conditions about a system's quality and performance, such as response time, processing time, and availability, are called non-functional requirements; together with functional requirements they are clarified and quantified in the system requirements definition process.
- In the Common Frame, the development processes run in the order planning → requirements definition → system design → software implementation → testing → acceptance. Distinguish the division of roles: requirements definition sets the goals, design decides the means of realizing them, and testing and acceptance confirm that they were achieved.
用語