An engineering change order (ECO), sometimes called an engineering change notice, is a formal document that authorizes and records a change to a product’s design, components, or bill of materials (BOM). It captures what is changing, why, which parts and revisions are affected, and who approved it. The point of an ECO is to make sure every change is reviewed, signed off, and traceable across engineering, purchasing, and production so nothing slips through informally.
How it works
An ECO usually starts with an engineering change request (ECR) that describes a problem or improvement. If the change is approved, an ECO is issued to execute it. A typical ECO lists the affected part numbers and revision levels, the old and new state, the reason (defect, cost reduction, supplier change, regulatory update), disposition of existing stock, and an effective date. Once approved, it becomes the record of truth for the new revision.
Why it matters
Uncontrolled changes cause mismatched parts, scrap, and orders built to the wrong spec. An ECO enforces a paper trail so manufacturing, quality, and suppliers all work from the same revision. It also protects traceability for warranty claims and audits.
How it applies to B2B quoting on Shopify
If you sell configured or made-to-order products, a change to a BOM or spec can change cost, lead time, and price. When an ECO updates a component or revision, refresh the affected product data before you quote so buyers do not accept a price built on an outdated spec. Reference the ECO revision on the quote line so both sides know exactly which version was priced. See the B2B quoting glossary for related terms like bill of materials and revision level.