This is a variant of connecting supplier data that uses all 3 scopes shared by the supplier. The alternative way of connecting supplier data to your calculations is using The spend-based hybrid method.
The supplier-specific method
One of the methods supported in the Normative calculation engine is the supplier-specific method. This method is a version of a supplier specific method from the Greenhouse Gas Protocol for scope 3 category 1 (purchased goods and services) and category 2 (capital goods). It is supplier specific since it uses only supplier-specific data to calculate the emissions, and no average data.
Calculation
The method takes the supplier’s scope 1, 2 and (parts of) 3 emissions data, divided by the revenue of that supplier. This yields supplier-specific intensity with an economic allocation, which is needed to calculate the company’s corresponding emissions based on the transaction amount with that supplier.
The method uses only the most relevant parts of the supplier's scope 3 emissions data, which in this case is the upstream categories. In order to make sure the calculation is performed with relevant data it also requires the supplier to have calculated and shared at least the following categories to unlock the functionality to perform a calculation:
- Category 3.1 - Purchased goods & services
- Category 3.4 - Upstream transportation & distribution
- Category 3.5 - Waste generated in operations
Once these three figures have been shared, it is possible to perform the supplier-specific calculation using scope 3 data. The calculation will include all upstream categories shared by the supplier.
Downstream categories are not included as it poses a risk of double accounting.
Recommended use of the supplier-specific method
The supplier specific method is recommended when your supplier has calculated their scope 3 data, and the quality of the data is deemed trustworthy and accurate. If your suppliers scope 3 data has been audited, especially by a trusted third party, it can usually be trusted.
Supplier-specific calculations tend to be more accurately applied when a product is purchased, rather than a service.