One issue I've seen is: assign the job to someone with experience as a instructor/mentor. A friend recently told me the story of a very predictable train wreck

One issue I've seen is: assign the job to someone with experience as a instructor/mentor. A friend recently told me the story of a very predictable train wreck at his company... management knew he had the background to do a good job with the training, but that wasn't the priority I guess. End result estimated to be ~3 person years wasted because of a lack of good training/process onboarding/mentoring. The newcomers weren't incompetent, but they needed more than they got.