If you refer to the IATF guidance to ISO/TS 16949:2002 para 7.4.1.2 states that the supplier refers to sites where production and/or service parts specified by the customer are manufactured. It then refers you to the ISO/TS 16949:2002 para 3.1.6
manufacturing
process of making or fabricating
- prodcution materials
- production or service parts
- assemblies, or
- heat treating, welding, painting, plating or other finishing services