It is interesting, to improve the reliability of its carbon footprint, to use EPDs from suppliers to calculate its emissions. To do this, it is necessary to add an EF in the tool, however, it is often not enough to integrate the total of the EPD.
An EPD calculates GHG emissions for the entire life cycle of an object:
Production (raw materials, their transport, and manufacturing),
Implementation (transport and installation),
Use,
End of life.
Each of these life cycle phases belongs to a different item in the carbon footprint.
In the case where the project's goal is to have a regulatory GHG export, it is possible to create a detailled EF between the different life cycle stages of the product, in order to be able to attribute each of the emissions related to these stages in the correct GHG category.
If the goal is to be able to analyze emissions in the tool based on the different items, it is more relevant to create different EFs for each part of the life cycle.
To create an EF, you can refer to this FAQ article. For a detailled EF, the instructions can be found in this article.