The procurement-process is currently being defined and described as a set of data formats and protocols under the EU-initiative CEN/TC 440. This is aimed at the government procuring products and services from private companies, but it will probably make sense for private customers as well.
Please note that the view shows this mostly from the customer point of view, not the vendor. For mapping of the procurement-services to application functions at the vendor, se the "sales, order, inventory management"-view.
More information is available at:
https://www.anskaffelser.no/generelt-om-verktoykassen/standardiseringsprosjekter-i-regi-av-eu/centc-440
https://standards.cen.eu/dyn/www/f?p=204:7:0::::FSP_ORG_ID:1976650&cs=175E298F320429229DD35C9E22F4E8F76