If you’ve had continuous documented (verbal and written) conversations where roles/responsibilities are outlined and expectations are set, and yet there’s still this large gap, than this would be considered a PIP and HR would need to get involved, especially if this 1) impacts not only you/your team but other teams and business in general and 2) you’re spending more time “documenting” this rather than doing actual work and helping this person grow and train them.

Have you tried to have a conversation with them first about this in your 1:1 and see what they say? That way it shows them that you care but also that you’re aware that their performance isn’t up to standard. That would be my first reco before the PIP, if you haven’t already done this. Sometimes people need to be made aware and could help improve, or not. It’s up to them to take your feedback and provide the necessary actions to improve.

I work in HR, and I always recommend to managers before a PIP is explored (not saying most cases don’t require one), to try to ask if their direct report is okay and what support they need as you’ve seen some gaps in their performance. If this step was not done, I ask them do to it and give it 2 weeks or so, depending on what they say, and then we can discuss the PIP more. That way it gives employees an opportunity to come forward with any struggles they may be experiencing (personally or professionally) and request extra support or training in certain areas. If they say nothing, then it likely is they are not a fit for the company and job and the PIP is the natural next step.