What is ECO (Engineering Change Order)?
A controlled document that authorizes and records a change to a product's design, bill of materials, or specifications.
Definition
An Engineering Change Order (ECO) is the formal mechanism for introducing a change to a released product, such as revising a component, updating a drawing, altering a specification, or changing a supplier-approved part. It captures what is changing, why, who approved it, the affected items and documents, and the effective date or serial or lot break at which the change takes effect. ECOs are often preceded by an engineering change request (ECR) that proposes the change and followed by an engineering change notice (ECN) that communicates it. Disciplined change control prevents the costly problems of building products to outdated specs, mismatched inventory, and uncontrolled BOM revisions.
How ECO Works in ERP
In ERP, an ECO ties to revision-controlled bills of materials and routings, applying the change at a defined effective date or unit break so the system knows which orders use the old versus new design. It typically routes through an approval workflow, updates affected documents, and can assess the impact on open orders and on-hand inventory of superseded parts. Strong PLM-integrated ERPs keep a full revision history so any past build can be traced to the exact design it was made from.
ERP Vendors with Strong ECO
Epicor Kinetic
ERP built for manufacturers — from job shop to enterprise
Rootstock Cloud ERP
Cloud ERP built on the Salesforce platform for manufacturers and distributors
Genius ERP
Purpose-built ERP for engineer-to-order and custom manufacturers
abas ERP
Flexible mid-market ERP for discrete manufacturers with global operations
Frequently Asked Questions
What is the difference between an ECR, ECO, and ECN?
An Engineering Change Request (ECR) proposes and justifies a potential change for review. An Engineering Change Order (ECO) is the approved authorization that defines and implements the change, including affected items and effective dates. An Engineering Change Notice (ECN) communicates the approved change to the people and systems that need to act on it. Not every organization uses all three, but they represent the propose, approve, and notify stages of change control.
How does an ECO affect open production orders?
An ECO carries an effective date or serial or lot break that tells the ERP which orders should use the new design and which keep the old. Orders already in process to the prior revision typically continue as-is, while new orders adopt the change, preserving traceability of what each unit was built to. Good systems also flag the impact on existing inventory of superseded components so it can be used up or dispositioned.