There is a simple trifecta of ingredients for all success. If someone has the skill for the task, the tools to complete it, and the effort to drive the endeavor, then they will – eventually – succeed.
So if someone doesn’t succeed, and it’s your job to figure out why and correct it, then your job isn’t actually all that hard.
You can usually figure out which one(s) of the three is missing via process of elimination. Start with what you know to be true: Have they done this successfully before? Then they have the skill, and likely the tools unless something has changed. So they’re lacking the effort – and addressing their motivation is different than trying to upskill them. Or, do you see them putting in consistent effort but not realizing the goal? Then you don’t have to motivate (or intimidate) them; you need to get them what they’re lacking.
Make that your checklist, reinforce it constantly. It will solve most of your problems!
The Opportunity Machine 