The answer is usually already in your history. The work is reading it properly: a lot of data, and someone who has worked with data long enough to pull a decision out of it.
Most businesses are sitting on years of their own data, and the answer to the question they are asking is usually inside it. The catch is that it does not announce itself. It takes someone who has worked with this kind of data to look at the haystack and know where the needle is, and what to do once they have it.
That is descriptive analysis: not a prettier chart, but the pattern that turns into an action you can defend, because the evidence is sitting right there in your own numbers. Here are two we have built, of the hundreds these become.
A rep left to their own judgement visits fifteen outlets and eleven are a waste of the day. We take the month's target, break it to each outlet on its own history, and plan each day around one high-value cluster, so the travel is tight and the time goes to the names that move the number. Pick a day to plot that day's route on the map.
A customer is on 15-day terms with a 1% early-pay discount. The ledger says he has never once paid before day 31. The discount is money given away for a promise he does not keep, and the same history tells you exactly when to call.