Engineering Change Order (ECO)
An Engineering Change Order (ECO) is the authorized, audited record of a change to a released product — the document that says what changed, why, when it takes effect (effectivity), and who approved it. ECO is the third stage of a three-stage change flow used across virtually every PLM system: the Engineering Change Request (ECR) raises the problem or proposal, the Engineering Change Notice (ECN) describes the fix and routes it for review, and the ECO authorizes implementation.
Why it matters
Change is the most-litigated process in any manufacturing company, and the ECO is the artifact regulators, auditors, and customers reach for first when something goes wrong. Without governed change, every downstream system — manufacturing, service, regulatory — is operating on assumptions. The ECR/ECN/ECO terminology is universal across PLM vendors and across industries; the difference between a mature PLM deployment and an immature one is not the existence of ECOs but whether they are routed automatically, signed electronically, and tied to specific effectivity rather than filed in a SharePoint folder after the fact.
External References
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Cite this definition
Finocchiaro, Michael. “Engineering Change Order (ECO).” DemystifyingPLM PLM Glossary, 2026, https://www.demystifyingplm.com/glossary/engineering-change-order-eco