Schedule of rates

A schedule of rates is what remains of a bill of quantities when the quantities are removed. The parties agree the rates up front; the work is then measured as it is actually done and paid at those rates. Schedules are the standard instrument for maintenance and term contracts, call-off frameworks, and — within lump-sum contracts — for valuing variations and change orders, where they remove one of the two arguments (the rate) and leave only the other (the quantity).

The known weakness is asymmetry of information at bid time. Because bidders do not know the eventual quantities, a schedule can be gamed by pricing items expected to occur frequently high and rarely-used items low, producing a schedule that looks competitive in total but is expensive in practice. Owners counter this with estimated-quantity weightings — which quietly reintroduces the take-off problem the schedule was meant to avoid.