ISO 9001 / 8.3. Design and development of products and services

This procedure for Design and Development of Products and Services should not be considered an external document if your organization performs these processes. According to ISO 9001:2015 an external document is documented information relevant to the quality management system and issued by an external entity such as customers, suppliers, legislators, regulators, standardization bodies, or business partners. As per the information you provide it seems that the design and development is not externalized so it is not considered an external document.

For more information about external documents and design and development in ISO 9001:2015 see the following materials:

- Article - What does external documents control mean in ISO 9001: https://advisera.com/9001academy/blog/2019/02/04/what-does-external-documents-control-mean-in-iso-9001/

-  Article - The ISO 9001 Design Process Explained: https://advisera.com/9001academy/blog/2013/11/05/iso-9001-design-process-explained/

- Book - Managing ISO documentation: a plain English guide - https://advisera.com/books/managing-iso-documentation-plain-english-guide/

- Free online training ISO 9001:2015 Foundations Course:  https://advisera.com/training/iso-9001-foundations-course/