Vacancy rates. Where do you include them in your analysis?

New investor here.  Hoping to get some opinions on where to factor in vacancy costs when you are analyzing a deal. I’ve seen several proforma from turn key companies include it in operating expenses as a variable expense but on the DealCheck website it has it subtract off the top of operating income. Doing it this second way shows properties cash flowing a lot less. I know at the end of the day, it should be factored in somewhere.  Just curious what best practices is?