An Engineering Change Notice (ECN) is the mechanism by which design or process changes are communicated, reviewed, approved, and implemented in a controlled manner. ECNs can be triggered by design improvements, customer requests, quality issues, cost reduction initiatives, or regulatory requirements.
The ECN process typically involves identifying the change, assessing its impact on existing inventory, open orders, tooling, and documentation, routing for approval through engineering, quality, and manufacturing stakeholders, and then implementing the change with proper effectivity dates.
Poorly managed ECNs are a leading cause of production errors. When a drawing revision is not propagated to the shop floor, parts get made to the old spec. When effectivity dates are ambiguous, some orders ship with old designs and others with new. A rigorous ECN process, supported by software that enforces revision control, prevents these failures.