I think his plan is putting the cart before the horse.

I think he put the cart before the horse because he started taking action before making a detailed plan.

We made plans for the picnic next week.

This report is very detailed.

Please tell me the details.

He started to act immediately.

I couldn't understand his actions.

I decided to start a new project.

He started playing the piano.

Since I started studying Japanese, I have been able to understand more about Japanese culture.