Primary vs secondary data, and why buyers ask for your primary data share
Two footprints for the same product can carry the same number and be worth very different amounts to a buyer. The difference is where the data came from. Footprints built on your own measured data tell a buyer about your factory; footprints built on averages tell them about the industry.
5 min read · Updated
- Your activity × your supplier's factorPrimary data
- Your activity × a database factorYour own quantities
- Typical activity × a database factorSecondary data
- Category defaultScreening proxy
Primary data
Primary data is measured for your product or your process: the kilowatt-hours on your meter, the fabric weight you cut, the fuel you burned, the emissions your supplier calculated for the yarn they sold you.
Secondary data
Secondary data comes from elsewhere: an industry average, a national grid factor, a database value for a material. It fills gaps and is often the only option for raw materials, but it describes a typical process, not yours.
How to raise yours
- Meter your own processes: a year of electricity and fuel per process is the single biggest step.
- Ask key suppliers for their own footprints for the materials you buy, in PACT format if they can.
- Record actual weights and losses rather than typical values.
- Update yearly, so the time rating stays good.
Start where you are
A footprint with a low primary data share is still useful, as long as it says so. Start with an estimate from a product link, then add your bills and materials in the full footprint form: each figure you add shows up in the primary data share.
Questions
What counts as primary data under PACT?
Data specific to the product's own processes and suppliers, as opposed to industry averages.
Is a footprint with 0% primary data useless?
No. It gives a first view of where emissions are. It should state its low primary data share.
Do data quality ratings use 1 or 5 as best?
In the PACT methodology, 1 is the best rating and 5 the weakest.