An engineering change order (ECO), also known as an engineering change notice (ECN), is the documentation necessary to complete an engineering change request (ECR). The engineering change request is a formal request to make a change to an engineered product or process. If an ECR is approved, an engineering change order is completed to provide the details and specifications necessary to make the required change.
Engineering change requests and change orders are necessary to create a thorough "paper trail" — though often the trail is really electronic. This paper trail records every change to a design, making it easy to go back to a previous iteration if necessary. If a new process turns out to be less efficient than the old one, or a new material becomes cost prohibitive, a thorough record of the previous process or product design ensures that the design can easily be returned to its prior version. The trail of documentation also shows stakeholders and customers that the company is working to fix problems and make improvements.
An engineering change order may be required for a variety of reasons. If the ECO is for a product, the designers may have discovered a problem that needs to be fixed or a way to fix a weakness in the product. A product may benefit from being upgraded with more advanced technology, or from a design that can be produced at a lower cost, for example. If the ECO is to change a process, it may improve efficiency, lower cost, or upgrade software or tools used in the process.
A thorough engineering change order updates any drawings and instructions necessary for producing a product or performing a process. It also updates any other relevant documents that are affected by the changes, such as user manuals and product prices. The ECO also should include an analysis of how the change improves the product or process and how much the change is likely to cost. It often includes a description of the change as well as drawings with the changes marked as well.
Once an engineering change order is produced, it must be approved by managers and possibly stakeholders, depending on the type and magnitude of the change. The ECO often undergoes several sets of changes during the approval process. Many companies streamline the process by using an electronic ECO system, which allows multiple users to suggest changes on the same document. Once changes to the ECO are addressed and approved by everyone involved, the engineering change order is complete and the changes can be made.