問44
頻出度★★★
システム開発プロジェクト遂行における品質管理を行うために, 開発工程の流れ図を作成した。当該流れ図の利用目的として, 適切なものはどれか。
平成26年度 春期 ITパスポート試験 問44
ストラテジ系企業活動 › 業務分析・データ利活用
This question's explanation and your answers so far.
解説
問 44
- ア
正解 The correct answer is ア. A flowchart shows the steps of a task or process in order from start to finish, making the flow, branches, and repetitions of a process visible. Once a flowchart of the development process is drawn, each stage — requirements definition → design → programming → testing — and the connections between them (where rework occurs, where a decision or check is inserted) can be seen at a glance. In quality control it is used to trace the process one stage at a time and to examine, stage by stage, what problems could occur at each point of the work (misunderstanding of specifications, missed reviews, handover mistakes, and so on), so that countermeasures can be prepared in advance. This is exactly what ア says — examine where in the work process and what kinds of problems could occur — which is the purpose of using a flowchart.
Incorrectイ
Judging whether a measured value such as a usage rate is within the predicted range is the role of a control chart. A control chart plots data in time order and draws a center line together with upper and lower control limits, showing whether the variation stays within the allowable range and whether any abnormal change has occurred. A flowchart has neither a time axis nor control limits, so it has no function for judging whether a number is within a range.
Incorrectウ
Systematically organizing the relationship between a serious problem (the characteristic) and its potential causes (the factors) is the job of a cause-and-effect diagram (fishbone diagram). The problem is placed on the spine, and causes branch out from major bones such as people, methods, and equipment down to smaller bones, making the causal relationships clear. What a flowchart expresses is the order and flow of a process, not the structure linking causes and effects.
Incorrectエ
Showing the frequency of problems by cause as a bar chart in descending order, and using the cumulative-percentage line to select the causes to tackle first, is the Pareto chart (the idea of focusing on the vital few, as in ABC analysis). Its purpose is to total and rank count data, so both its tool and its aim differ from those of a flowchart, which depicts the flow of a process.
ここがポイント
- The purpose of using a flowchart in quality control is to visualize the work steps in process order and to examine in advance what problems could occur at which stage.
- How the main QC charts differ: flowchart = grasp the flow of the process; cause-and-effect diagram = organize the link between a problem and its causes; Pareto chart = grasp the frequency by cause and focus on the vital few; control chart = judge whether variation stays within the control limits.
用語