This is a critical skill in big companies where everyone is swamped and busy and things get lost. I do this all the time when I’m dealing with people who don’t answer their email, or who tend to stall and delay approvals, or people who are just very busy. I’ll Email and describe the problem and then say the magic phrase “If I don’t hear back from you in [N] days, I am going to do XYZ on [DAY N].” This way I’m not asking for approval and then helplessly waiting and pinging. I’m putting them on notice. XYZ is going to happen unless you get off your butt and stop me.

Occasionally someone will come back weeks later, angry that I did XYZ without telling them, and I always have a paper trail showing that they were the ones who dropped the ball.