#Analysis of 14 reinforced bridge bills of quantities has shown that an integrated cost and time model containing at most 20 elements at the detailed design stage can predict total project value within accuracy ± 3%. Using the same number of elements the model can predict the project duration within accuracy: ± 5%. Quantity-significant work packages (qswp) were derived using trade- by- trade analysis, and a single cost model factor (cmf), and time model factor (tmf) were determined. Since the same elements used in the cost model are also used in the time model, a new approach to developing operational bills of quantities is highlighted. The new operational bill makes deriving and using the evaluation curve of a project much easier.