問6
頻出度★★☆
システムのライフサイクルプロセスの一つに位置付けられる，要件定義プロセスで定義するシステム化の要件には，業務要件を実現するために必要なシステム機能を明らかにする機能要件と，それ以外の技術要件や運用要件などを明らかにする非機能要件がある。非機能要件だけを全て挙げたものはどれか。 a 業務機能間のデータの流れ b システム監視のサイクル c 障害発生時の許容復旧時間
平成30年度 春期 ITパスポート試験 問6
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 6
Incorrectア
This option chooses a, c. Choice a, the data flow between business functions, represents the system's own behavior of what data passes from which business function to which, and is a system function to realize business requirements, that is, a functional requirement. Therefore ア, which includes a, does not list only non-functional requirements and is incorrect.
Incorrectイ
This option lists only b. Choice b is indeed a non-functional requirement, but choice c, the allowable recovery time when a failure occurs, is also a non-functional requirement related to availability, and it is omitted here. Since the question asks to list all non-functional requirements, イ, which lacks c, is incorrect.
- ウ
正解 The non-functional requirements defined in requirements definition refer to quality and condition aspects such as performance, availability, operation, and security, other than the business functions themselves (what the system does). Choice b, the cycle of system monitoring, is an operational requirement about how the system is operated and monitored, not a business function itself, so it counts as a non-functional requirement. Choice c, the allowable recovery time when a failure occurs, is an availability requirement about how quickly to recover from a failure (related to RTO, the target recovery time), which is also a non-functional requirement as a technical requirement. The option that lists all and only the non-functional requirements is b and c, so the correct answer is ウ.
Incorrectエ
This option lists only c. Choice c is a non-functional requirement, but choice b, the cycle of system monitoring, is also an operational non-functional requirement, and it is missing. Since it does not list all the non-functional requirements, エ is incorrect.
ここがポイント
- Grasp the distinction: functional requirements are the system functions necessary to realize business requirements (what it does), while non-functional requirements are quality and condition aspects other than that, such as performance, availability, operation, and security.
- Data flow between business functions is classified as a functional requirement, while the cycle of system monitoring (operation) and the allowable recovery time when a failure occurs (availability) are classified as non-functional requirements.
用語