Man power supply or business auxilary/support service

Hi My question for today is

If a Company engages Outside agency in its in house production facility, which includes supply of required manpower for such production or packing task.

Billing is done based on production completed, i.e to say rate/Kg or Rate/Unit basis(not as no. of people employed for said task)

So, Does the engagement come under Manpower supply, business support service?

please Answer with reasoning