expression
reinventing the wheel
Idiomatic expression meaning to waste effort creating something that already exists, often used critically.
新しいシステムを作るより、既存のものを使ったほうがいい。車輪の再発明は避けるべきだ。
Rather than building a new system, it's better to use an existing one. We should avoid reinventing the wheel.
Calque of the English idiom 'reinventing the wheel'.