問45
頻出度★★★
プロジェクトチームが実行する作業を, 階層的に要素分解した図表はどれか。
平成27年度 春期 ITパスポート試験 問45
マネジメント系プロジェクトマネジメント › プロジェクトマネジメント
This question's explanation and your answers so far.
解説
問 45
Incorrectア
A DFD (Data Flow Diagram) is a diagram used in business analysis and design that shows where data flows from and to within a business or system, using four symbols: data flow, process, data store, and external entity. What it expresses is the flow of data, not a hierarchical breakdown of a project’s work.
- イ
正解 WBS (Work Breakdown Structure) is a tree-shaped chart that organizes a project’s deliverables and work by breaking them down hierarchically, from large units into smaller and smaller elements. The elements at the lowest level are called work packages, and the breakdown continues until each package is small enough that its owner, effort, duration, and cost can be estimated without splitting it further. This prevents work from being overlooked and provides the basis for schedule and cost estimates and for assigning responsibility. The stem’s “diagram that breaks the work performed by a project team down hierarchically into elements” is exactly the definition of WBS, so the correct answer is イ.
Incorrectウ
An arrow diagram (PERT chart) is a scheduling technique in which each activity is drawn as an arrow to show the order of activities (their dependencies) and the number of days each takes, so that the critical path and the amount of slack can be calculated. It deals with the sequence and timing of activities, not with breaking work down hierarchically into elements.
Incorrectエ
A milestone chart places the planned completion dates of a project’s key checkpoints (milestones) — such as design completed, testing started, or delivery — along a time axis in order to manage progress. It only shows the timing of those checkpoints; it does not break the work itself down into a hierarchical structure.
ここがポイント
- WBS = a chart that breaks a project’s work (deliverables) down hierarchically into elements. Effort, duration, cost, and the responsible person are estimated per work package, the smallest unit, which keeps work from being overlooked.
- Telling project-management diagrams apart: WBS = hierarchical breakdown of work; arrow diagram (PERT chart) = order of activities and the critical path; Gantt chart = schedule and progress of activities shown as horizontal bars; milestone chart = timing of key checkpoints. DFD alone belongs to the development process (business analysis) side and is not a project-management diagram.
用語