ECR:Engineer Change Request Engineering Change Request/Application
ECN:Engineer Change Notification Engineering Change Notification
ECO:Engineer Change Order Engineering Change Order
Chinese explanation: ECR engineering change request (before change) When the engineering data user finds that there is a problem with the data and needs to request to change the data, fill in this form.
After receiving the ECR, the ECO engineering department believes that it is necessary to make changes to the engineering data, and issues this order.