問23
頻出度★★★
ABC 分析の説明として, 適切なものはどれか。
平成22年度 春期 ITパスポート試験 問23
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 23
Incorrectア
The description of a method that systematically grasps what causes defects by means of a diagram resembling a fish skeleton is a cause-and-effect diagram (fishbone diagram, Ishikawa diagram), not ABC analysis. A cause-and-effect diagram places the result (the characteristic) at the end of the backbone and writes out factors such as people, machines, materials, and methods as branches in order to organize the causes. It is one of the seven QC tools and does not rank items by importance.
Incorrectイ
The description of a method that analyzes whether there is a relationship between two variables using collected data is correlation analysis (scatter diagrams or regression analysis). What it handles is the strength of the association between two variables, so both its purpose and its procedure differ from ABC analysis, which sorts items by amount and then ranks them by cumulative composition ratio.
Incorrectウ
The description of a method that takes samples from a population, inspects them, and judges the quality of the population by the number of defective items in the samples is sampling inspection. It is a quality-inspection scheme that judges whether a lot passes or fails by statistical inference, and it has nothing to do with ABC analysis, which sets priorities among the targets to be managed.
- エ
正解 エ is correct. ABC analysis is a method that sorts products, inventory items, customers, and the like in descending order of an indicator such as sales amount or inventory value, calculates their cumulative composition ratio (cumulative percentage), and classifies them into rank A, rank B, and rank C. Based on the Pareto principle (the 80-20 rule), which says that a very small number of top items account for most of the total amount, it applies careful management to rank A, whose contribution in amount is large, and simple management to rank C, whose contribution is small, thereby setting clear priorities in how management resources are allocated. The wording in エ — a method that ranks items by importance based on the cumulative composition ratio of sales amounts, etc., in order to clarify which items should be managed with priority — states exactly this core of ABC analysis, namely ranking by cumulative composition ratio, so it is appropriate.
ここがポイント
- ABC analysis: a method that sorts items in descending order of sales amount or inventory value, divides them into the three ranks A, B, and C according to the cumulative composition ratio, and thereby clarifies which targets deserve priority management. The Pareto principle (a small number of top items account for most of the whole) provides its theoretical backing, and a Pareto chart is used to visualize it.
- Telling confusable analysis methods apart: use a cause-and-effect diagram (fishbone diagram) to organize causes systematically, correlation analysis (scatter diagram) to analyze the association between two variables, and sampling inspection to judge whether a lot passes. Be able to identify each one by what it aims at and by what kind of data it handles and how.
用語