平成23年度秋期 ITパスポート試験問42

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問42

頻出度★★★

新営業店システム開発プロジェクトの作業を，図のように階層的に表現する手法はどれか。

新営業店システム開発プロジェクト
├─ 要件定義
├─ システム設計
├─ プログラミング
└─ 結合テスト
   ├─ テスト計画
   │  ├─ 品質基準定義
   │  └─ テスト計画書作成
   └─ テスト実施

出典　平成23年度秋期 ITパスポート試験問42

解説

問 42

Incorrectア
PERT is a method in which you draw an arrow diagram (network diagram) that connects activities with arrows and nodes, and then use the precedence relationships and durations of those activities to obtain the earliest and latest start dates and the critical path, thereby managing the schedule. What it expresses is the “order, dependency and time” between activities, not a hierarchical structure that decomposes an upper-level activity into lower-level ones. The figure has neither arrows nor durations, so it does not apply.
イ
正解 The correct answer is イ, WBS (Work Breakdown Structure). WBS is a method that takes the work required to achieve a project's objective and breaks it down step by step, starting from the whole project at the top, into smaller units of work, expressing the result as a hierarchical structure (a tree). The figure has exactly this shape. Level 1 is “New sales branch system development project”; level 2 is “Requirements definition”, “System design”, “Programming” and “Integration testing”; at level 3 “Integration testing” splits into “Test planning” and “Test execution”; and at level 4 “Test planning” splits into “Quality criteria definition” and “Test plan document creation”. The whole diagram consists only of containment relationships in which an upper-level activity equals the set of its lower-level activities. The fact that there are no arrows showing the order of the work and no durations written in also matches the characteristics of a WBS. Breaking work down hierarchically in this way makes it easier to prevent omissions, assign people in charge, estimate effort and cost, and set the units of progress management (work packages).
Incorrectウ
Structured programming is a programming technique in which a program is assembled using only the three basic structures of sequence, selection and repetition, so as to produce a program that is easy to understand and easy to maintain. Its target is the control structure of source code, not a method for decomposing and representing the work of a project (such as requirements definition or integration testing).
Incorrectエ
The function point method scores the number and difficulty of the functions seen from the user's point of view, such as external inputs, external outputs and internal logical files, and estimates development effort and cost from the resulting size of the software. Its output is an estimated value (a number); it does not depict work hierarchically in a diagram.

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WBS (Work Breakdown Structure) = a method that subdivides a project's work level by level starting from the top and lists it exhaustively in a hierarchical structure. The smallest unit produced by the breakdown (the work package) becomes the basic unit for assigning responsibility, estimating effort and managing progress.
How to tell project management diagrams apart: decomposed by hierarchy (parent-child / containment) → WBS; order and schedule shown with arrows and durations → PERT (arrow diagram); the period of each activity shown as a horizontal bar → Gantt chart.

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解答問42イ

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平成23年度 秋期 ITパスポート試験 問42

問 42