This factor offsets the overstatement of costs when Cost Estimating Format factors are applied to large projects with repetitive work elements that allow workers to achieve above-average productivity.

Economies of scale are either zero or a decrease in cost resulting from task or project size. For example, the crew productivity for replacing a roof can exceed average for large roofs with few penetrations or interior parapets

Typically, unit costs are based on projects of a known size range. Use of these costs for projects outside of this range can result in inaccurate estimates. This concept also applies to other factors in the Cost Estimating Format. Therefore, economies of scale are the best approach to adjusting productivity in Part A for unit prices.