問11
頻出度★★★
製造業の A 社では, 製品の組立てに必要な部品を購買している。A 社では, 自社の仕入金額全体に占める割合が大きい部品を, 重点的に在庫管理を行う対象として選びたい。このとき利用する図表として, 適切なものはどれか。
平成23年度 特別試験 ITパスポート試験 問11
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 11
Incorrectア
A Gantt chart puts tasks on the vertical axis and time on the horizontal axis, and uses horizontal bars to show the start and end dates and the progress of each task; it is a chart for process and schedule management. It is useful for planning a project schedule and grasping progress, but it has no function for showing each part’s share of the total amount in descending order, so it cannot be used to select targets for focused management.
Incorrectイ
A control chart plots measured values in time order and draws a center line with upper and lower control limits, in order to judge whether a process is in a stable state (whether an abnormality has occurred). It is one of the seven QC tools. Its purpose is to monitor variation in quality, which is different from arranging parts in descending order of amount to narrow down the priority targets.
Incorrectウ
A cause-and-effect diagram (fishbone diagram) takes a result (characteristic) and sorts the possible causes into categories such as people, machines, materials, and methods, laying them out in the shape of a fish skeleton so that the causes can be identified. It helps to structure causes, but it is not a chart that quantitatively shows shares of an amount, so it is not suitable for selecting the parts to be managed as priorities.
- エ
正解 The correct answer is “エ Pareto chart”. A Pareto chart combines a bar graph, in which items are arranged in descending order of count or amount, with a line graph showing the cumulative percentage; it visualizes the Pareto principle that most of the whole is accounted for by a small number of important items. In this question, by arranging the parts in descending order of purchasing cost and looking at the cumulative percentage, the company can identify the small number of parts (group A) that account for most of the total purchasing cost. This is exactly ABC analysis in inventory management: group A is given strict ordering and inventory control, while groups B and C are managed more simply, which is what focused management means. Therefore, the chart best suited to the purpose of selecting the parts that account for a large share of the total purchasing cost as targets of focused management is the Pareto chart.
ここがポイント
- A Pareto chart consists of a bar graph with the items arranged in descending order plus a line showing the cumulative percentage, and it is used to find the small number of important items (a focus-on-the-vital-few approach). In inventory management it serves as the basis of ABC analysis, used to select group A, the items with a large share of the total amount, as the targets of focused management.
- Learn to tell the seven QC tools apart: a Pareto chart narrows down the priority items, a control chart monitors the stability of a process, and a cause-and-effect diagram identifies causes. A Gantt chart is not one of the seven QC tools; it is a chart for process and schedule management.
用語