5.5 End of life management

EOL is a financial event, not just an operational stop. A poorly managed discontinuation results in “Stranded Inventory” (dead cash) or “Service Gaps” (breach of contract). The objective is a controlled landing: zero residual inventory liability and 100% fulfillment of contractual service obligations.

Phase 1: the LTB sequence (last time buy)

The Product Discontinuation Notice (PDN) triggers the countdown. Synchronization between component availability and customer demand is critical.

Timeline protocol

1. PDN Issuance (T-Minus 6 Months): Formal notification to customers. Must include:
   • Reason for EOL (e.g. component obsolescence, technology refresh).
   • Last Order Date (LOD).
   • Last Ship Date (LSD).
2. LTB Window: The period for customers to place final orders.
3. Validation: Cross-check LTB orders against raw material availability.

Commitment requirements:

• LTB orders from customers act as NCNR (Non-Cancelable, Non-Returnable) agreements automatically, with no exceptions permitted.
• Critical component EOL announcements by the manufacturer require securing necessary component stock prior to issuing the formal PDN to the customer. This prevents market scalping and ensures manufacturing capability.

Pro-Tip: LTB must not be calculated based on current run-rates. Customers will “hoard” or “dump” inventory based on their own product transitions. A hard PO commit must be forced; a forecast must not be trusted.

Phase 2: final build & service stock planning

The Final Build is the last opportunity to manufacture Finished Goods (FG) and Spare Parts. Once the line is dismantled, re-initialization costs are prohibitive.

Service stock calculation

Enough spares must be banked to cover the warranty period (e.g. 3-5 years).

Formula:

Required Spares = (Active Install Base x Failure Rate (%)) x Remaining Warranty Years + Safety Buffer

Production logic

• Scrap Allowance: 3–5% raw material overage must be added. If a shortage on a $0.10 resistor occurs during the final build, the $500 unit cannot be completed.
• Yield Lock: Process changes (Engineering Change Orders, ECOs) must not be introduced during the final build. Stability > Optimization.

Phase 3: disposition & liability (Excess & Obsolete, E&O)

After the Last Ship Date, remaining materials are liabilities (Excess & Obsolete).

Liability assignment

• Unique Parts: Customer pays 100%. These were bought specifically for their Bill of Materials (BOM).
• Common Parts: Factory (Contract Manufacturer, CM) absorbs or returns to distribution (restocking fee applies).
• Work in Progress (WIP): Must be completed to Finished Goods (FG) or scrapped immediately.

Tooling disposition

• Consign: Ship molds/fixtures to the customer (if they own them).
• Store: Archive for 3-5 years if service builds are possible.
• Destroy: If proprietary IP is at risk, definitively destroy molds and issue a Certificate of Destruction (COD) with photographic evidence.

Phase 4: documentation & archiving

When the team disbands, tribal knowledge evaporates. The “DNA” of the product must be archived to ensure future questions can be answered without the original engineers.

The “golden archive” structure

1. Manufacturing Data: Final BOM, Gerber Files, Pick & Place Files, Stencil designs.
2. Test Environment: Firmware images (hex/bin), Test Fixture schematics, specific test limits/scripts.
3. Compliance: CE/FCC certificates, Safety Reports, UL files (essential for legal defense).
4. Master Sample: Keep 2x Golden Samples + 2x Known Bad Units (for test calibration).

Final Checkout: End of Life (EOL) Management

Control Point	Critical Threshold / Action	Logic / Risk
Financial Terms	NCNR Signed	Without NCNR, a customer cancellation leaves you with unsellable scrap.
Material Audit	Clear the Pipeline	Cancel open POs with vendors immediately after the Final Build calculation.
Service Stock	Allocated distinctly	Segregate service stock from general inventory. Do not accidentally sell your warranty buffer.
ERP Status	Set to “Obsolete”	Block new sales orders in the system. Prevent “Ghost Orders.”
Tooling	Disposition Signed	Molds take up space and rust. Get a decision: Ship, Store, or Scrap.