Most KPIs, if not all, are related in some way to other KPIs. What you would have to establish, which is likely impossible, is that one KPI is necessary and sufficient to move another KPI in a very tightly controlled way. Firstly, you can only establish that kind of cause and effect with a very tightly controlled, randomized trial study.
In most cases, you wouldn't even be able to establish that one KPI was even necessary to move the other. Finally, even if you have a decent correlation between two KPIs, you would impact the second KPI in a very probabilistic way where a formula or algorithm would yield a rather deterministic result. That's not valid when we live in a multi-variate, probabilistic one.
I think the better solution is to measure each KPI separately and independently.