Engineering Change Notice (ECN)

What is an Engineering Change Notice (ECN)

An engineering change notice (ECN), or change notice, is a document which records and authorizes a change to a drawing or design.  ECNs is an integral part of engineering best practices and provide the controls and documentation necessary to ensure that changes are recorded and can be found by the right person at the right time. 

An ECN must contain at least this information:[2]

  • Description of the change. This includes a drawing of the component before and after the change. Generally, these drawings are only of the detail affected by the change.
  • Identification of what needs to be changed. This should include the part number and name of the component and reference to the drawings that show the component in detail or assembly.
  • Reason(s) for the change.
  • Approval of the change. As with the detail and assembly drawings, the changes must be approved by management.
  • Instruction about when to introduce the change—immediately (scrapping current inventory), during the next production run, or at some other milestone.[3]