問43
頻出度★★★
情報システムの品質マネジメントの考え方に関する記述a～dのうち, 適切なものだけを全て挙げたものはどれか。 a PDCAサイクルによる継続的な取組みが, 品質の改善には有効である。 b 多くの機能をもつシステムほど品質が高い。 c 欠陥の予防コストは, 不具合発生時に是正するコストよりも一般的に少ない。 d 適切な設計や製造によって品質を高めることができる。
平成27年度 春期 ITパスポート試験 問43
マネジメント系システム開発技術 › システム開発技術
This question's explanation and your answers so far.
解説
問 43
Incorrectア
The combination a, b, d. It includes the incorrect statement b (the more functions a system has, the higher its quality), which already makes it inappropriate, and it also drops the appropriate statement c (prevention cost is lower than correction cost). It fails the requirement of listing all and only the appropriate statements on two counts.
Incorrectイ
The combination a, c. Both statements it includes are appropriate, but it leaves out d (quality can be improved through appropriate design and manufacturing), which is equally appropriate. The question asks for the option that lists all and only the appropriate statements, so missing a correct statement already makes it wrong.
- ウ
正解 The correct answer is ウ (a, c, d). The basic idea of quality management is that quality is not something you find by inspection, but something you build into the process. Statement a is exactly continuous improvement — running Plan-Do-Check-Act to surface problems and feed them into the next plan — which is the standard route to better quality. Statement c reflects quality-cost thinking: prevention costs such as reviews and test design are generally smaller than the rework costs (redesign, retesting, incident response, loss of trust) that arise when a defect appears after release and has to be corrected, so preventing problems upstream is cheaper. Statement d states the principle that quality is raised by reviews and standardization at the design stage and by building quality in during the manufacturing (implementation) process, which is also appropriate. Only b is wrong, so ウ, which lists the three statements a, c and d, is the answer.
Incorrectエ
The combination c, d. It lacks the appropriate statement a (continuous improvement activities based on the PDCA cycle are effective for improving quality). PDCA is the core improvement cycle of quality management, so a combination that excludes it does not satisfy the requirement of listing all of them.
ここがポイント
- Quality is not something sorted out by inspection; it is built in through appropriate design and manufacturing. The number of functions (quantity) and quality (how well requirements are met) are different things, so having more functions does not mean higher quality.
- The quality-cost principle: prevention costs (reviews, test design, standardization) are generally smaller than the correction costs incurred after a defect occurs. The further upstream defects are prevented, the lower the total cost, and continuous improvement through the PDCA cycle is the means of driving this.
用語