since already many have talk about some of the examples, there are some benefits of ECO. following good ECO practices it will make thing easier when documenting a full history of what change have been made to a product and when they occurred. In industries with regulatory requirements, like the medical device industry, having a full history of every change to a product is mandatory. (Depending on the industry, change orders and even the change process itself may be audited by a regulatory body.) Keeping a record of product changes will also help you debug any problems that occur after your product launches. The task of identifying and fixing the root cause of any problem is easier when you have a complete product change history.