ECNs are used to formally track design changes and corrections through which phases?

• A. Concept development
• B. Production
• C. Project prototyping and life-cycle phase
• D. Never used

Answer: (C)

Engineering Change Notices provide a formal, auditable way to capture, approve, and implement every modification to a design, its documentation, and the manufacturing plan. This formal change-control process is most appropriate through project prototyping and the product’s life cycle, covering the rapid iterations during development and the ongoing updates that occur after release for production support, improvements, and field fixes. In prototyping, changes are common and must be tightly controlled to avoid cascading rework, while in the life cycle they ensure that all related artifacts—CAD models, drawings, bills of materials, procedures—remain synchronized as the product evolves. Early concept development tends to be more exploratory and informal, with formal ECN tracking beginning as the design moves into prototyping and into the life cycle.