Eftersom du inte har lagt till den engelska texten, vet jag inte med bestämdhet vad de refererar till, men inte ska det väl vara utförarroll. Googla order så hittar du utföranderoll i olika texter.

Spekulativt.

Tänkte först att utförarrollen syftar på den som hanterar (executes) en beställning men insåg sedan att:
utföra en beställning = place an order

Passar det in i sammanhanget? Eller ska det kanske vara den som hanterar på beställningsmottagarens sida (föreslagsvis "executing role")?

The contractor 'performs' or 'provides' the same service that the public agency used to provide directly. You seem to be dealing with the public procuremet process here. This is where the Swedish system (basically following EU guidelines, and there is a directive invovled) separates the political decision to procure services, like building roads or running an healthcare clinic of any kind) from the practical process of delivering/providing those services. (Have seen that this system is alos used in the UK). The 'Konkurrensverket' has a lot of fun reading on this in both Eng and Swe -- suggest starting with the LOU -- lagen om upphandling. then there is reading gracefully provided by the EU.

In this context I don't think I have ever seen 'executional role' -- and not 'order-placing' either. You are right in your discussion that this is closer to the 'procurement' side.