How to replace estimations and guesses with a Monte Carlo simulation
I tried this at a past job. I fed Jira history into a Monte Carlo simulation that would give a set of 
probabilities for various completion timeframes for any new user story. Despite months of trying to sell the idea, backed by sound mathematics instead of guesses, I never got past the point where stakeholders would listen politely then immediately go back to demanding to know "when will it be done"