Adjustable Staff Hours Calculation - Live Estimate

So I have an interesting thing to share from OUAC conference this year.  A rather simple formula was shared for doing an estimation of where your store should be in terms of staff hours worked at a particular time during the day.  The calculation is simple and all info is already in the Day Book of RAI.  It works as follows...

Let's say it is 2pm and our buys are $1500 and our sales are $2000.

{(3 x $buys) + Sales}  / 140           {(3x1500) + 2000}  / 140 = 46.43 hours

Note that the 140 is a constant that can be adjusted based on the brand and the efficiency of your workers/store.  This formula is useful.  For instance in this case, the manager could look at the live calculation of this based on the live DRS data and see an hour total estimate live.  Our managers use this to determine whether to call in staff (you are significantly lower than the calculated value) or send workers home (you are significantly over).