Productivity is the ratio of the output produced to the inputs needed to produce it, such as labour hours, plant hours or materials.
In construction estimating, productivity is usually expressed as an output rate, for example square metres of blockwork laid per gang hour or cubic metres excavated per machine hour. These outputs drive the labour and plant element of unit rates, so a small change in assumed productivity can have a large effect on the price. Quantity surveyors also use productivity when assessing disruption claims, comparing outputs achieved on affected work with outputs on unaffected work, an approach often called a measured mile analysis. Factors that commonly affect productivity include:
- site access, congestion and working conditions
- weather and time of year
- design changes and late information
- the skill and experience of the workforce
Related terms: output, all-in labour rate, unit rate, disruption.
