Engineering Change Request: Definition, Process and When to Use One

What Is an Engineering Change Request?

An engineering change request (ECR) is the document that starts the engineering change process. It describes a problem with an existing design, specification, material, or process, or an opportunity to improve one, and proposes a modification to address it. Submitting an ECR does not authorize any change; it requests that engineering review the proposal and decide whether to proceed.

The ECR feeds into a formal review process. If approved, it is converted into an engineering change order that authorizes implementation, and an engineering change notice that communicates the change to affected departments. If rejected, the ECR is closed with an explanation. If incomplete, it is returned to the originator for more information.

The ECR process exists to ensure that changes are evaluated before they are implemented. It prevents informal, undocumented modifications that erode configuration integrity and create discrepancies between what the documentation says and what is actually installed on equipment in the field.

Who Can Submit an Engineering Change Request?

ECRs can be submitted by anyone who identifies a valid reason to modify a design or process. In practice, they originate from several sources:

Maintenance technicians. Field technicians frequently observe design problems before engineering does. Fasteners that corrode too quickly, access points that make service dangerous, components that fail consistently at the same location; these are the kinds of observations that become high-quality ECRs when properly documented. Maintenance is an underused source of ECRs in many organizations.

Quality engineers. Inspection data that shows consistent defects, out-of-tolerance conditions, or warranty failures often leads to ECRs proposing a design or process fix.

Manufacturing engineers. Difficulty building to the current design, excessive scrap rates, or assembly errors that trace back to a specification trigger ECRs to improve producibility.

Customers. Customer complaints or performance feedback may require a design change. In some supply chain relationships, customers have direct authority to submit ECRs to their suppliers.

Suppliers. When a raw material or component is discontinued, a supplier may submit an ECR proposing a qualified substitute. This triggers a formal review of the substitute's technical compatibility before it is used.

Regulatory bodies. Updated safety standards or certification requirements may mandate design changes, which are submitted as ECRs and processed with the appropriate urgency and approval authority.

What an ECR Document Contains

A complete ECR gives reviewers enough information to evaluate the problem, assess the proposed solution, and make a decision. The core elements are:

Problem description. A clear statement of what is wrong or what could be improved. Vague ECRs ("component needs improvement") are difficult to evaluate and frequently returned for clarification. Specific ECRs ("bearing in position X fails within 500 hours of service due to inadequate lubrication access") are evaluated quickly.

Supporting evidence. Failure data, maintenance records, quality inspection results, safety incident reports, or customer complaints that substantiate the problem. Evidence makes the ECR credible and helps reviewers prioritize it against other pending changes.

Affected items. The specific part numbers, assemblies, drawings, specifications, or processes that need to change. Reviewers need to know the scope of the change to assess its impact.

Proposed change. A description of what the submitter proposes to do, even if the engineering team ultimately designs a different solution. The proposal helps reviewers understand the submitter's intent and may be adopted, modified, or replaced with a better approach.

Expected benefits. The anticipated improvement in reliability, safety, cost, manufacturability, or performance. Quantified benefits, where possible, help prioritize the ECR against other demands on engineering resources.

Urgency and priority. An assessment of how quickly the change is needed, particularly if the current design poses a safety risk, is causing production stoppages, or is driving significant warranty or maintenance costs.

The ECR Review Process

Once submitted, an ECR goes through a structured review. The review body, often called an engineering change board (ECB) or change review board (CRB), evaluates the ECR against several criteria:

Technical validity. Does the proposed change actually solve the stated problem? Is the approach technically sound? Are there unintended consequences for other parts of the design?

Impact assessment. What is the effect on cost, production rate, quality, spare parts inventory, maintenance procedures, and regulatory compliance? A change that fixes one problem while creating another in a different area may need to be redesigned before approval.

Classification. Is this a major change (affecting interchangeability, safety, or regulatory status) or a minor change (no effect on form, fit, or function)? Classification determines the approval authority and the urgency of implementation.

Disposition decision. Approve and issue an ECO, reject with explanation, or return for more information. Approved ECRs move to the ECO stage. Rejected ECRs are closed out with a documented rationale. Returned ECRs are revised and resubmitted.

Why Maintenance Teams Should Use ECRs

Maintenance technicians have direct, daily contact with equipment. They observe failure patterns, difficult-to-access service points, wear patterns that indicate design problems, and safety hazards that engineering staff may never see. This field intelligence is valuable, but only if it reaches engineering in a usable form.

An ECR is the formal mechanism for converting a field observation into an engineering action. Without it, the observation may be noted informally, forgotten, or acted on in a non-standard way. With it, the observation enters a review process that can produce a permanent design fix, a procedure update, or a supplier change that eliminates the root cause.

Consider a bearing that fails repeatedly in a particular motor application. The maintenance team replaces the bearing and moves on. But submitting an ECR that documents the failure frequency, the failure mode, and a hypothesis about the cause, such as an inadequate lubrication interval, incorrect bearing specification, or a misalignment issue in the mounting, gives engineering the information needed to investigate and fix the problem permanently. This is the connection between maintenance execution and reliability improvement at the design level.

Linking ECRs to maintenance documentation and equipment records in the asset management system creates a traceable chain from field failure to design resolution, which supports both ongoing maintenance planning and longer-term reliability improvement programs.

ECR vs. Work Order: Knowing Which to Use

An ECR and a work order address different kinds of problems. A work order covers maintenance tasks on existing equipment: replacing a failed component, performing a scheduled inspection, or repairing a fault. It does not change the design; it restores the equipment to its current specification.

An ECR is appropriate when the current specification itself is the problem: when the same repair keeps being made repeatedly because the design is inadequate, when a component consistently fails before its expected service life, or when a process generates systematic defects that point to a specification problem.

In practice, both documents are often needed together. A work order addresses the immediate failure; an ECR initiates the investigation into why the failure keeps happening. Organizations with strong maintenance and reliability programs use both systematically.

Common Questions About Engineering Change Requests

Conclusion

The engineering change request is where design improvement begins. For maintenance teams, it is the formal channel for turning field observations into engineering action. Organizations that encourage maintenance technicians to submit ECRs, and that have a process for reviewing and acting on them, close the feedback loop between operational experience and design quality, which is the foundation of long-term equipment reliability.