An informal pip.

You can tell someone they need to improve their performance. You can help them make a plan. And you can help evaluate the result.

Making a plan can certainly help.

You don't need to involve HR inorder to make a plan.

(Not saying that pip isn't a good concept, just that a formal pip is a last resort kind of tool)

I’ve always assumed that’s a prerequisite for a pip. Obviously managers need to give reports good feedback regularly.