KPIs that ask for quantitative responses in physical units usually require the use of primary data—data that are directly related to the activities in question and specific to your supply chain, as opposed to data based on industry or regional averages. An example of a calculation that requires primary data is:
Calculate B1 as the average of the most recent irrigation water use intensity estimates from the growing operations that produced your crop supply, weighted by the mass supplied by each growing operation.
Primary data should always be used unless the Calculation & Scope guidance states otherwise. In some agricultural supply chains, where the collection of primary data has been estimated to be too difficult or costly, the KPI guidance allows the use of regional estimates. However, your calculation should not combine regional and primary data. Rather, calculate your response using what primary data do have and only use regional data if you have no primary data available. Because regional data is not equivalent to primary data, the supporting percentage is always reported as 0%. A statement like the one below will be included in the Calculation & Scope if regional data may be used:
If primary farm data are unavailable for any of your crop supply, you may use a regional estimate to answer B1. Do not combine primary data and regional estimates…If you have reported a regional estimate for B1, then report 0% for B2.