問33
頻出度★★★
システム開発プロセスには，システム要件定義，システム設計，プログラミング，テスト，ソフトウェア受入れがある。新規のシステム開発において，開発の初期の段階でシステム要件として定義するものはどれか。
平成25年度 春期 ITパスポート試験 問33
マネジメント系システム開発技術 › システム開発技術
This question's explanation and your answers so far.
解説
問 33
Incorrectア
The system's hardware configuration (the configuration of servers and network devices) is a deliverable of the system design (system architectural design) process, which decides by what means the fixed requirements will be realized. At the requirements definition stage, you only state the required performance and availability as non-functional requirements; you do not go so far as to decide the concrete hardware configuration that satisfies them.
Incorrectイ
The system's development standards (coding conventions, document formats, development procedures, and so on) are agreements on the project planning and quality management side that define how development is to be carried out; they are not requirements placed on the system (system requirements). They are work rules for the development side, on a different level from what users ask of the system.
- ウ
正解 The correct answer is ウ. In system requirements definition, the first process of system development, you decide “what this system will achieve and how far it will cover”. That is, you first fix the boundary of the target business operations, the target departments, and the data and functions to be handled (the target range, i.e. the scope), and on that basis you identify the functional requirements (what functions are needed) and the non-functional requirements (quality levels such as performance, availability, and security). If the target range stays vague, the later system design, programming, and testing cannot determine what is to be built, which invites endless additions of requirements during development (scope creep) and gaps in understanding at acceptance. That is exactly why the target range is a system requirement that should be agreed with stakeholders in the early stage of development, and among the choices ウ is the only one that expresses what to build rather than how to build it.
Incorrectエ
The system's test plan is created in order to verify requirements and designs that have already been fixed, so at an early stage where the requirements are not yet settled you cannot write down what should be verified. A test plan is drawn up based on the content of the requirements definition and the design and is carried out in the testing process; it is later work, not something defined as a system requirement.
ここがポイント
- System requirements definition sits at the very upstream of the development process; it is the process that determines the target range (scope) of systemization together with the functional and non-functional requirements, that is, what to build.
- Keep the division of processes straight: how to realize things, such as the hardware configuration, belongs to system design; development standards belong to development planning and quality management; and the test plan is later work that follows once the requirements are fixed. None of them is a deliverable of system requirements definition.
用語