Rocke's post is interesting and certainly relevent, although I would caution you with the
http://www.tuvps.co.uk/uploads/imag...9_0607_B16EN Certification of OEM Devices.pdf as it relates specifically to OEM devices which isn't applicable to you.
The reason for your NB requiring an audit of your sub contractor is because it does not hold 13485 certification or (I'm guessing) 9001. They therefore have concerns about the quality of the product you receive.
Your supply agreement must be robust enough to control the quality of the product. It should contain all the requirements you would expect to be carried out by the supplier. At the very least it should cover
- validation and verification of processes and machinery
- training/competence requirements for staff
- traceability and record control of all appropriate activities, including training, batches etc.
- Calibration requirements
- handling of non-conforming product
That's even before you go down the actual requirements for the product!
It may be worth going through ISO 13485 and covering each requirement, ask yourself...Is this something the supplier should be doing to ensure the quality of my product? if it is, include a requirement for it in your agreement.
If you were working with a company with ISO 13485 and probably 9001, you could assume a lot of this and just require the continual renewal of QMS certification, your NB wouldn't have to audit them either!
One question....you say that you arrange the sterilisation, do you or the customer do the packaging prior to sterilisation? If they package the devices for you, they are still part of the sterilisation process.