A PEF/OEF evidence record should make the boundary visible before anyone drafts claim language. For PEF, that means the product function, quantity, duration, quality level, and reference flow. For OEF, that means the organisation, reporting interval, goods and services in the product portfolio, and any excluded part of the organisation or portfolio.
The method evidence should also show how impact assessment was handled. The 16 Environmental Footprint categories are climate change, ozone depletion, particulate matter, ionising radiation, photochemical ozone formation, acidification, terrestrial eutrophication, freshwater eutrophication, marine eutrophication, freshwater ecotoxicity, human toxicity cancer effects, human toxicity non-cancer effects, land use, water use, mineral and metal resource use, and fossil resource use. Classification assigns inventory flows to categories; characterisation converts those flows into category indicators. Normalisation, weighting, and aggregation are later steps and should not hide a material adverse category.
Data quality matters because primary and secondary data choices affect reproducibility and comparability. The method expects company-specific data for foreground processes under the organisation's control and uses a Data Needs Matrix to determine requirements for other processes. Record which processes use measured company data, supplier-specific data, EF-compliant secondary datasets, generic proxies, or assumptions.