By subtracting a measured unit productivity rate during an impacted period from the unit productivity rate during an unimpacted period, the resulting value represents:

This calculation is the basis of the "measured mile" analysis, a widely accepted method for quantifying lost productivity. It compares the productivity rate during an unimpacted period (the "measured mile" or baseline) against the rate achieved during an impacted period. The difference between these two rates represents the quantifiable loss in labor productivity caused by the impacts or disruptions. This value is crucial for substantiating claims for additional costs due to inefficiency.

A. Acceleration: This is the act of completing work faster than planned, not a calculation of lost efficiency.
B. Production output: This is the physical quantity of work completed (e.g., cubic yards of concrete), not a rate difference.
D. Productivity efficiency: This is typically a ratio, such as the earned value divided by the actual cost (Cost Performance Index), not a subtraction of rates.

1. AACE International

Recommended Practice No. 25R-03

"Estimating Lost Labor Productivity in Construction Claims

" (June 28

2004)

Section 4.2

p. 8. This section describes the measured mile approach

which is founded on comparing productivity in an unimpacted period to an impacted period to determine the loss.

2. Zayed

T. M.

& Halpin

D. W. (2004). Productivity and cost regression models for pile construction. Journal of Construction Engineering and Management

130(6)

779-789. https://doi.org/10.1061/(ASCE)0733-9364(2004)130:6(779). The paper discusses methods of measuring productivity

where loss is the deviation from an established norm or baseline rate.