I believe you are mentioning ISO 9001:2015 clause 6.3 Planning Changes.
Clause 6.3 is about planning how to handle changes without breaking the quality management system, that is keeping its integrity. For example, when an organization moves to a new location or introduces a set of new production equipment it is necessary to plan the introduction of these changes in a controlled way. Or when an organization decides to outsource parts of the production process for the first time. Or decides to start a new production line, or merges with another organization. Some years ago, I worked with an injection molding company that duplicated the number of machines and changed location to another site, with a lot of new workers recruited – that was a great change in planning, operating, and controlling production. 6.3 is about changes like this.
The following material will provide you information about planning and controlling changes: