ECO and ECN Process Across PLM and ERP

The vocabulary is not standardized, but the common usage is consistent enough. An engineering change request (ECR) is a proposal: someone thinks something should change and explains why. An engineering change order (ECO) is the authorized work package: it lists what changes, who approves, and what the new design looks like. An engineering change notice (ECN) tells everyone downstream that the change is released and when it takes effect.

Some companies merge these into a single ECO form with stages. That is fine. What matters is that the three functions exist: a request that can be rejected cheaply, an approval gate with the right people, and a broadcast that reaches the shop floor and purchasing, not only other engineers.

Smaller shops often skip the ECR and discover the cost later, when every engineer's idea becomes a formal order. A light triage step before the ECO saves approvers from reviewing changes that were never going to be made.

Engineering checks form, fit and function. Manufacturing checks that the plant can build it with current tooling and that routing and work instructions can be updated by the effective date. Purchasing checks supplier lead times, minimum order quantities and open purchase orders. Quality checks inspection plans and first article needs.

For aerospace and defense, add configuration management and, where the product is subject to customer approval, a class I or class II classification that decides whether the customer must approve. For medical devices, the design history file and risk file updates belong in the same ECO.

Set service levels for each approver, for example two working days, with escalation. Slow ECO approval is one of the most common reasons engineers make unofficial changes on the floor, which then break traceability.