Demonstration

'Top-down' cost estimating retains a valuable role even as detailed 'bottom-up' estimating becomes possible and emphasis switches from forecasting to accountancy and control.

Estimate Costs

The comprehensiveness of 'top-down' techniques guards against the chronic tendency of 'bottom-up' methods to underestimate. The unque architecture of FACET models makes optimum use of design characteristics as they emerge with increasing certainty.

Bottom-up estimates can include only those work elements which ae identified and planned for in advance of work commencing. Hence, they must invariably be underestimates of the total. While invaluable for day-to-day project management and cost control, they are unsuitable thus for high-level decision making which must depend upon comprehensive top-down estimates.