Engineering Change Orders (ECOs): How to Manage Engineering Changes, Revisions and Approvals Without Rework

An engineering change order (ECO) is a formal, approved document that authorizes a specific change to a product, part, drawing or technical document. It records what is changing, why the change is needed and who signed off on it. Engineering managers, design engineers, document control specialists and quality teams use ECOs to make sure every change is reviewed and authorized before anyone builds, installs or maintains it.

Consider a familiar situation. A field crew arrives at a substation to replace a protection relay, working from a single-line diagram they printed from a shared drive. Engineering updated that drawing four months ago, but the update never made it past an email thread. The crew wires the relay to the old design. No one catches the mistake until commissioning, and the utility pays for the same job twice.

That is rework, and it rarely begins with a bad change. It begins with a change that was not communicated. This article explains what an engineering change order is, how the change and approval process works and how controlled revisions keep engineering, design and document control teams working from the same current information.

What is an engineering change order (ECO)?

An engineering change order (ECO) is the document that authorizes an approved change and defines exactly what it involves. It typically records the affected parts, drawings or documents, the reason for the change, the assessed impact, the new revision level, the effective date and the approvals behind it. The ECO is the authorization step: it comes after a change has been requested and reviewed, and before the change is communicated and put into effect.

Formal change control is a recognized discipline rather than an internal convention. ISO 10007:2017, Quality management, Guidelines for configuration management, treats change control as one element of configuration management, alongside configuration identification, status accounting and configuration audit.

ECOs apply to manufactured products and to engineering documents alike. In discrete manufacturing, attention falls on parts and bills of materials (BOMs). In asset-intensive operations, it falls on drawings, specifications and as-built records, which is where this article concentrates.

ECO vs. engineering change request (ECR) vs. engineering change notice (ECN)

Three documents move a change from idea to implementation, and they are easy to confuse.

Usage varies. Some organizations combine the order and the notice into one document, and some industries name or sequence the three differently. What matters isn't the naming convention, but whether proposal, authorization and communication each happen and are recorded.

The engineering change order process, step by step

Most organizations follow a version of the same six steps.

1. Identify and request the change. Someone raises an ECR describing the problem or opportunity, the items affected and the proposed fix.
2. Assess the impact. Reviewers weigh the effect on cost, schedule, safety, compliance, interfaces and downstream documents. Careful assessment here prevents surprises later.
3. Create the ECO. The order captures the approved scope of the change, the documents and assets it touches, the new revision level and the effective date.
4. Review and approve. A change control board or equivalent cross-functional group approves or rejects the order. Membership usually spans engineering, operations, quality and, where relevant, procurement.
5. Implement and update the documents. Teams revise the affected drawings, specifications and records, and the previous revision is superseded rather than deleted.
6. Release and communicate. An ECN or equivalent notification tells every affected group what changed and what they need to do about it.

A controlled process is what keeps every stakeholder working from the current, approved revision. The last two steps are the ones most often compressed under deadline pressure, and a change that is approved but never distributed leaves teams working from superseded information.

Best practices for engineering change management

Engineering change management succeeds or fails on document discipline. The practices below target the conditions that produce rework.

• Maintain a single source of truth. One controlled repository should hold the current revision of every drawing and specification. Copies on local drives and in email threads are how superseded documents stay in circulation, so strong document control practices underpin everything else on this list.
• Use clear, consistent revision numbering. Anyone opening a drawing should be able to tell at a glance whether it is current, in review or superseded.
• Define the approval workflow in advance. Name reviewers by role, set the sequence and agree on turnaround expectations. Ambiguous approval paths are a common source of delay.
• Keep a complete audit trail. Record who changed what, when and on whose authority. An engineering document management system captures this automatically as a by-product of the workflow.
• Retire superseded drawings from circulation. Field and contractor teams should reach the current revision easily, and the older ones only through a clearly marked history.

Most rework traces back to an uncontrolled or out-of-date document rather than to the change itself. The change was usually sound. The problem is that not everyone who needed to know found out in time.

Engineering change order software: How a document management system prevents rework

Spreadsheets and shared drives can track changes for a while. They tend to strain once change volume grows, once several sites share engineering standards, or once an auditor asks for evidence that a specific revision was approved by a specific person on a specific date.

Engineering document management software makes control a property of the system rather than a matter of individual diligence. When you evaluate options, look for:

• Version and revision control that makes the current revision unmistakable
• Configurable approval workflows that route changes to the right reviewers and record each decision
• A complete audit trail covering every revision, approval and access event
• Concurrent engineering support, so several people can work on related documents without overwriting each other
• Controlled distribution, including secure printing, so superseded drawings do not reach the field
• Integration with the systems your teams already use, such as computer-aided design (CAD), enterprise asset management (EAM), computerized maintenance management system (CMMS) and enterprise resource planning (ERP) platforms

Several vendors serve this market, and the right fit depends on your industry, portfolio and existing systems. Accruent RedEye is one option built for asset-intensive environments, with version management, configurable workflows, comprehensive audit trails, concurrent engineering and integrations to EAM, ERP, Office and CAD applications. As an indication of scale, Accruent reports that Aurora Energy, a New Zealand power distribution company with a 20-person engineering team, uses RedEye to manage more than 21,000 engineering drawings across 40 substations, reducing the version-control errors and rework caused by its previous system.

For a wider view of evaluation criteria, our guide to document control software walks through the features worth weighing before you shortlist.

Simplify engineering change management with Accruent

Engineering change becomes manageable once revisions and approvals live in one controlled system. The change itself is rarely the problem. Rework happens when the approved revision and the revision in someone’s hands are not the same document.

To see how controlled revisions, enforced approvals and a full audit trail work in practice, explore our engineering document management software and request a demo. We will walk you through it.