Our Data Cards provide detailed information about the selected resource. One section on the environmental profile tab provides the 'Q metadata' percentage.
Q Metadata explained
The Q Metadata is calculated from variation attributable to the datapoint product specificity, plant specificity and manufacturer specificity following the Carbon Leadership Forum methodology. The CLF methodology calculates the square roof of sum of each of the adjusted uncertainty factors. Each adjusted uncertainty factor is the square of it's underlying factor.
Manufacturer specificity: +/- 2% when products are declared by one organization owning facilities where products are made, and +/- 20% otherwise.
Facility specificity: +/- 2% when data is manufacturer specific and when only one manufacturing facility is used in the data, and +/- 20% otherwise.
Product specificity: +/- 2% when data is manufacturer specific and represents one performance specification, and +/- 20% otherwise.
If the LCA results are expected to vary by less than 10%, the EPD is considered product specific.
Known limitations: Product specificity is currently not filled in for any resources. This means that all resources get 20% from product specificity.
The default equation for the Q Metadata % is as following:
Q Metadata % = √(Z1^2 + Z2^2 + Z3^2)
Z1 = Manufacturer Specificity
Z2 = Facility Specificity
Z3 = Product Specificity