問34
頻出度★★★
システム開発を上流工程から下流工程まで順番に進めるとき, システムの利用者によるテストの段階で大幅な手戻りが生じることがある。それを防ぐために, 早い段階で試作ソフトウェアを作成して利用者の要求事項を明確にする方法はどれか。
平成22年度 秋期 ITパスポート試験 問34
マネジメント系ソフトウェア開発管理技術 › 開発プロセス・手法
This question's explanation and your answers so far.
解説
問 34
Incorrectア
Object orientation is a way of thinking about software design and development in which data and the operations (procedures) on it are bundled together as a single object, so that parts become easier to reuse and to maintain. It is an idea about how to build the structure of a program; it is not a way of proceeding through the development processes (a development model), nor is it a method of checking the users' requirements with a trial product.
Incorrectイ
The spiral model is a development model in which the system is divided into subsystems with high independence, and a cycle of design, implementation and testing is repeated so that the system is completed step by step. Its main point is reducing risk through iteration; it is not a term defined as a method whose purpose is to create trial software in order to clarify the users' requirements. The one that corresponds directly to the definition in the question is prototyping.
Incorrectウ
The data-centered approach (DOA) is a technique that carries out analysis and design by focusing on the structure of, and the relationships between, the data handled in the business. It makes use of the property that data structures stay stable even when business procedures change, and it has nothing to do with a method of building a trial product to check the users' requirements.
- エ
正解 The correct answer is エ, Prototyping. Prototyping is a way of carrying out development in which working software that serves as a trial product (a prototype) is built at an early stage, and users actually try it out so that the requirements can be checked and settled. With the approach described in the question, where work proceeds in order from upstream processes to downstream processes (the waterfall model), the first time users can see something that actually runs is the final testing stage, so if they discover there that it is not what they had imagined, a major rework going all the way back to design occurs. Prototyping makes up for this weakness by showing users trial versions of the screens and operations at an early stage before completion, so that gaps in understanding are removed in advance. This matches exactly what the question describes: creating trial software at an early stage to clarify the users' requirements.
ここがポイント
- Prototyping (the prototyping model) = a development model in which a trial product is built at an early stage of development and confirmed by the users, so as to prevent major rework in later processes caused by misunderstandings about the requirements.
- The waterfall model proceeds from upstream to downstream without going back, so when a mismatch in requirements is found downstream, the rework is large. As typical development models that make up for this weakness, be able to tell the prototyping model and the spiral model apart (settling the requirements with a trial product, versus completing the system step by step by repeating cycles).
用語