Change notice (ECN)
Also called engineering change notice, ECO, engineering change order
A change notice (ECN, or ECO in many companies) is the approved instruction to carry out a change: it holds the tasks, the affected and resulting objects, and the release, so the new revisions go out together.
In Windchill the change notice groups change tasks, one per piece of work, and releases the new revisions as a set. Companies use “ECN” and “ECO” for the same thing; we follow whatever the client already says.
The number of change notices a product needs is a useful health check. Many of them are fixing things manufacturing could have caught before release.
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Last reviewed November 2026 by Element Consulting
