問45
頻出度★★★
既に稼働中のシステムに機能を追加するために，プログラムの一部を変更した。本番稼働してよいかどうかを判断するために，稼働中のシステムに影響を与えることなくテストを行う環境として，最も適切なものはどれか。
平成21年度 春期 ITパスポート試験 問45
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 45
Incorrectア
A programming environment is where developers write code and check unit-level behavior, and its configuration and data volume are usually very different from production. Working there is no guarantee that it will work in production, so it is not sufficient evidence for judging whether the program may go live.
Incorrectイ
A test environment for another system is built on premises that differ from the target system. It does satisfy the condition of not affecting the running system, but because it is not equivalent to production, it cannot correctly determine whether the program may go live. It also causes a separate problem: it would interfere with testing of the other system.
Incorrectウ
Testing on the production environment itself directly contradicts the condition of carrying out the test without affecting the running system. If there is a defect, actual business operations could stop or production data could be destroyed, so this option must absolutely be avoided.
- エ
正解 The correct answer is エ, “A test environment equivalent to the production environment.” This question asks for an environment that satisfies two conditions at the same time. First, it must not affect the running system, so the testing has to be done in a separate environment isolated from production. Second, it must allow you to judge whether the program may go live in production. To determine whether the modified program will also run correctly in production, the test environment must match production as closely as possible in OS, middleware, hardware configuration, data volume, and so on; otherwise, passing the test is no guarantee that it will work in production. The environment that meets both requirements is a test environment that is independent of production yet has a configuration equivalent to it. When a function is added to a system that is already running, you must check not only the added function itself but also run regression testing to confirm that existing functions are not broken, so the standard practice is to verify everything comprehensively in a production-equivalent environment before migrating.
ここがポイント
- A test environment should be independent of the production environment (blocking any impact on the running system) and at the same time have a configuration equivalent to production (ensuring the test results are valid). Meeting both conditions is the prerequisite for judging whether the program may go live.
- When adding a function to a system that is already running, check not only the added part but also run regression testing in a production-equivalent environment to confirm that existing functions are not broken, and only then migrate.
用語