Supplier development process

Answer:

Suppliers for IATF 16949 certified organization must go through supplier development process. Requirements for suppliers of IATF 1696 certified companies are much higher than usual. For example, suppliers must be ISO 9001 certified, second party audits must be done and etc.
Standard requires exactly:
The organization must prioritize supplier development actions. Determination inputs for this prioritization must include the following:
Assessment of supplier performance (see 8.4.2.4)
Findings from second-party audits (see 8.4.2.4.1)
Status of QMS certification (see 8.4.2.3)
Risk analyses
The organization must implement actions necessary to resolve supplier performance issues and bring about continual improvement

I would like to suggest a Checklist for Evaluation of Suppliers- https://advisera.com/16949academy/documentation/checklist-for-evaluation-of-supplier/
And a d etailed explanation of audit types at IATF 16949 Audit Types & How they Affect Process Improvement- https://advisera.com/16949academy/blog/2017/11/01/iatf-16949-audit-types-how-they-affect-process-improvement/

thank you Ivan
Do I understand correctly that distributors are considered the same as suppliers as it relates to 8.4.2.3?

Distributors are considered as sales partners, so requirements for suppliers in 8.4.2.3 are not related to them. There is no specific requirement for distributor development process.