The Absence Rate, and the Output It Actually Costs

How to read this sheet

This is a steady-state line and a mean, which is exactly what absence is not. Real absence is lumpy - a Monday, a festival week, one operation losing three people at once - and a line that survives its average day can still lose a fortnight to a bad one. Reserves sized on this sheet protect the average and will be short on the days that matter, so treat the figure as a floor and add for the variance the plant knows it has. The reserves are also assumed interchangeable and instantly deployable, which is the strongest assumption here: a floater who cannot set a sleeve is not cover for the sleeve operation, and the skill matrix decides whether these numbers mean anything at all. Cover absorbed by neighbours is entered as a share and is the least reliable input on the table, because it is rarely measured and usually estimated by the person who arranged it. Nothing here models work in progress, which is what actually shields a line from a short absence: a buffer ahead of the binding operation buys time that this sheet, running everything as an instantaneous chain, cannot see - so a line with generous inter-operation stock will lose less than this says, and a single-piece flow line rather more. Finally, the answer is one line. A plant that moves people between lines is running a larger and more forgiving system than this models, and the honest use of the sheet there is per line, to find which one is bleeding.