Reinvent the wheel

Meaning

To unnecessarily duplicate a basic process or design that already works perfectly well. It is a warning against wasting effort on problems that have already been solved.

Practical, impatient

Used in a sentence

• Let us just use the existing template instead of trying to reinvent the wheel.
• There is no need to reinvent the wheel for this marketing campaign.
• He spent three weeks building a new filing system when he could have just used the old one instead of reinventing the wheel.