Engineering Change Order (ECO) – Definition & Template

This article defines engineering change orders (ECOs), describes the role it plays in product design and manufacturing.

What is an engineering change order?

An engineering change order (ECO) is a documentation packet that outlines the proposed change,
This article defines engineering change orders (ECOs), describes the role it plays in product design and manufacturing.

What is an engineering change order?

An engineering change order (ECO) is a documentation packet that outlines the proposed change, lists the product or part(s) that would be affected and requests review and approval from the individuals who would be impacted or charged with implementing the change. ECOs are used to make modifications to components, assemblies, associated documentation and other types of product information.

Where does an ECO fit in the engineering change management process?

The change process starts when someone identifies an issue that may need to be addressed with a change to the product. It ends when the agreed-upon change is implemented. ECOs are used in between to summarize the modifications, finalize the details and obtain all necessary approvals.

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The stages of the engineering change process are:

  1. Issue identification & scoping:

    Someone identifies a problem or issue and determines that it may require a change. The scope of the issue and its possible impact are estimated.
  2. ECR creation:

    An engineering change request (ECR) is created to examine the necessity and feasibility of the change, to identify parts, components and documentation that might be affected, to estimate costs and to list the resources required to implement the change.
  3. ECR review:

    The ECR is circulated for review and discussion among key stakeholders and is modified as needed.
  4. ECO creation:

    Once the ECR is approved, an engineering change order (ECO) is generated, which lists the items, assemblies and documentation being changed and includes any updated drawings, CAD files, standard operating procedures (SOPs) or manufacturing work instructions (MWIs) required to make a decision about the change.
  5. ECO review:

    The ECO is then circulated to a change review board made up of all stakeholders (including external partners when appropriate) who need to approve the change.
  6. ECN circulation:

    Once the ECO has been approved, an engineering change notification/notice (ECN) is sent to affected individuals to let them know that the ECO has been approved and the change should now be implemented.
  7. Change implementation:

    Those responsible for implementation use the information in the ECO and ECN to make the requested change.
While an engineering change order is used for changes that are executed by engineering, other types of change orders may be used by other departments. These include the:
  • Manufacturing change order (MCO) —

    A change order describing modifications to the manufacturing process or equipment.
  • Document change order (DCO) —

    A change order detailing modifications to documents, specifications or SOPs.

ECO benefits

While you may groan at the prospect of pulling together another set of documentation, an ECO is a critical part of keeping product development on track and making sure product information is accurate. A good ECO contains the full description, analysis, cost and impact of a change, and a good ECO process ensures that all stakeholders have bought in to the change. Having an organized method of handling product changes reduces potential design, manufacturing and inventory errors, minimizes development delays and makes it easy to get input from different departments, key suppliers and contract manufacturers. Following good ECO practices also makes it easy to document a full history of what changes have been made to a product and when they occurred. In industries with regulatory requirements, like the medical device industry, having a full history of every change to a product is mandatory. (Depending on the industry, change orders and even the change process itself may be audited by a regulatory body.) Keeping a record of product changes will also help you debug any problems that occur after your product launches. The task of identifying and fixing the root cause of any problem is easier when you have a complete product change history.

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  • Reduced engineering cycles by 90%
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Without a clear ECO process in place, making a change to a product can set off a chain of costly, time-consuming and avoidable events. Take a part switch that happens late in the development process. Engineering may tell manufacturing to be aware of the new part, but if that information is never conveyed to the purchasing department, the old part will be ordered. When the components arrive, manufacturing will not be able to assemble the product, and its launch will be delayed until the new part is obtained (most likely with some rush charges incurred along the way).

Engineering change orders make it possible to accurately identify, address and implement product changes while keeping all key stakeholders in the loop and maintaining a historical record of your product. Without them, miscommunications occur that lead to delays, incorrect purchase orders and improper product builds.

Engineering Change Orders: Paper-based vs. electronic software systems

Managing ECOs With Paper/Manila Folders Managing ECOs With Electronic Systems
Cycle Time
  • ECO is generally reviewed one person at a time
  • If multiple copies are distributed, edits must be consolidated and reviewed again
  • Paper ECO can be misplaced
  • ECO review can be a long process (weeks)
  • ECO can be reviewed by many people at once
  • All edits are made to a single version, so no consolidation is needed
  • ECO is always available online
  • ECO review is significantly shorter process (days)
Signature Process
  • Early approvers won’t be aware of edits, necessitating additional rounds of review
  • Official approval disappears if the ECO file is lost
  • Harder to maintain clean, complete history of changes
  • All approvers sign off on the same set of documentation
  • Electronic signature is 21 CFR part 11 compliant, a requirement for the medical device industry
  • Automatic maintenance of clean history for audits
Issue Resolution
  • Individuals need to be tracked down to resolve problems
  • May need to wait for change control review board meeting to connect with other approvers
  • People’s comments can be viewed, so hold-ups can be quickly resolved
  • Can easily see who hasn’t signed and request approval electronically
Package Format
  • Large paper file of documents and drawings must be printed
  • Tedious and labor-intensive to pull together information from many locations
  • Electronic documentation is environmentally friendly
  • Easy to create and access ECO when managed in the same system as underlying product information


Companies need to be able to adapt quickly in today’s constantly changing environment, and often that means making changes to their products. Engineers make modifications during development and production with the intent of adding functionality, improving manufacturing performance or addressing the availability of a particular part. To make sure proposed changes are appropriately reviewed, a solid process is critical—especially if members of your product team are scattered across multiple locations (for instance, design engineers in Boston, the manufacturing team in St. Louis and component manufacturers all over the world). At the heart of a solid change process is the engineering change order. Learn how Arena PLM can help you control your engineering change process, reduce your change order cycle times and eliminate ambiguity when communicating product changes to your extended supply chain.

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