Percent within limits, an acceptance method that uses the mean and standard deviation of a lot's test results to estimate the share of material that meets spec. It rewards consistency as well as hitting the target, because a wide spread lowers PWL even when the average is perfect. PWL feeds a pay equation, and many agencies pay full price near 90 PWL, with bonuses above it and deductions below.
Voids average fine but the spread's killing us, PWL's 74 on lot 6, that's money straight out of the bonus.
Also heard as
- percent within limits
Related terms
Pay factor
A multiplier applied to the contract price for a lot of asphalt based on its test results.
QC/QA
Quality control and quality assurance: contractor testing to run production and agency testing to verify it.
Density
How tightly a compacted asphalt layer is packed, reported as a percentage of its maximum theoretical density.