Write an engineering change notice with a full impact check

Help me write an engineering change notice (ECN/ECO) and check its impact. Parts and documents affected: [part numbers, current revisions, drawings, BOMs, routings] The change: [what changes, from what to what] Reason: [cost reduction / quality fix / supplier change / customer request / obsolescence / regulatory] Proposed effectivity: [date, serial number, lot, or "use up existing stock first"] Industry or customer rules: [e.g. customer must approve form-fit-function changes, PPAP resubmission, FDA design control, AS9100, or "none"] First, classify the change: does it affect form, fit, or function? Is it interchangeable with the old revision? That decides whether the part number should change or just the revision; explain your reasoning and mark it [ENGINEERING TO CONFIRM]. Then check impact on: - Inventory: raw material, WIP, finished goods, open purchase orders, and stock at the customer or in service (use up, rework, or scrap) - Suppliers: drawings to reissue, tooling changes, first article inspection - Production: routings, work instructions, fixtures, programs, gauges, operator training - Quality: PFMEA, control plan, inspection plans, PPAP or first article requirements - Service and spares: interchangeability with fielded units - Cost: one-time costs and per-unit change - Regulatory and customer notifications Return: 1. The ECN text: change description, reason, affected items with old/new revisions, disposition of existing stock, effectivity, and approvals required. 2. An impact checklist with an owner and due date for each item. 3. The risks if this is implemented without the checks. Do not invent part numbers, revisions, or costs; use [ADD].