問13
頻出度★★☆
製造業において利用されているCADの説明として, 適切なものはどれか。
平成26年度 秋期 ITパスポート試験 問13
This question's explanation and your answers so far.
解説
問 13
Incorrectア
Calculating the quantity of materials required to match the production plan, and going as far as arranging (ordering) those materials, is a description of MRP (Material Requirements Planning). What it deals with is a materials procurement plan — when, what, and how many items to procure — so it targets a different process from CAD, which supports the design work itself.
Incorrectイ
Managing information such as the parts, intermediate products, and required quantities needed for manufacturing is the role of production-management and MRP-type systems built around a bill of materials (BOM, parts list). That is about managing quantity information for the parts that make up a product, and it is not a description of CAD, which supports the design work of drawing up plans.
Incorrectウ
Bringing together and centrally managing product information from design through manufacturing — design drawings, parts lists, and so on — is a description of PDM (Product Data Management). Drawing data produced by CAD does become an object managed by PDM, but PDM is a mechanism for integrating and managing data, whereas CAD is where the design work itself is carried out, so their roles differ.
- エ
正解 CAD stands for Computer Aided Design. It moves the design and drafting work that used to be done with a drawing board and pencil onto a computer, supporting tasks such as creating, revising, and reusing drawings, calculating dimensions, and checking for interference. Compared with drawing by hand, revising a drawing or reusing part of one is much easier, so the productivity of design work goes up; and because the computer handles dimensions and consistency mechanically, human error decreases and reliability improves as well. Choice エ says exactly that it “uses computers in product design to improve the productivity and reliability of the design work,” which matches the definition of CAD, so it is the correct answer. Note also that the mechanism for passing design data created with CAD to the manufacturing process and using it to control machine tools is called CAM (Computer Aided Manufacturing), and the mechanism for analyzing and verifying a design through simulation and the like is called CAE (Computer Aided Engineering); it is good to learn these together with CAD.
ここがポイント
- CAD (Computer Aided Design) = computer-aided design: using computers in the design and drafting process to raise the productivity and reliability of design work.
- Telling the related manufacturing terms apart: CAM supports the manufacturing process, CAE analyzes and verifies a design, MRP is material requirements planning, and PDM centrally manages product information from design through manufacturing.
用語