At the start of your shift, your supervisor sends you to finish the repair job Bob is working on. Being safety-smart, you walk down the drawings to conduct lockout/tagout before starting. You put your locks and tags right alongside Bob’s.
You get out to the job, and don’t see Bob. “Ah, he must be removing his locks and tags.” No proper shift change occurred; you should have gone to the job first and had Bob walk down lockout/tagout with you.