According to ISO 9001:2015 Clause 8.4.1, “The organization shall retain appropriate documented information of the results of the evaluations, monitoring of the performance and re-evaluations, of the external providers.”
There should be an evaluation and approval process for external providers. External providers and their ability to deliver products or services that meet the requirements needs to be evaluated on a periodic basis, and approved. The criteria for evaluation shall include their quality of products or services, credibility and reliability of delivery, production capacity, maintining quality management systems such as ISO 14001/ISO 9001 Certification and commitment to prices. Assessing supplier performance has many more benefits other than merely meeting the requirements fof ISO 9001:2015. It helps your organization to control cost, ensure quality shorter delivery time and improved relationships .