I don’t have much experience in Engineering change order. Thank you SMK45 for sharing your experience.From my research i found the stages of the engineering change process are
1. Issue identification & scoping
2. ECR creation: An engineering change request (ECR) is created to examine the necessity and feasibility of the change, to identify parts, components and documentation that might be affected, to estimate costs and list the resources required to implement change.
3. ECR review: Review and discussion among key stakeholders and is modified as needed.
4. ECO creation: Once the ECR is approved, and ECO is generated, which list the items, assemblies and documentation being changed including any updated drawing, CAD files , SOP, MWI(Manufacturing work instruction) required to make a decision about the change
5. ECO review: ECO is circulated to change review board made up of all stakeholders who need to approve the changes
6. ECN circulation : Once the ECO has been approved, an Engineering change notification/notice is sent to affected individuals to let them know.

7. Change implementation: Those responsible for implementation use the information in ECO and ECN to make the make the requested change.