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 termination: zero residual inventory liability and 100% fulfillment of contractual service obligations.

Phase 1: the LTB sequence (last time buy)

The Product Discontinuation Notice (PDN) initiates the formal EOL process. 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.

Strict Constraint

LTB must not be calculated based on current run-rates. Customers will “hoard” or “dump” inventory based on their own product transitions. A firm purchase order commitment is required; forecasts are not acceptable.

Phase 2: final build & service stock planning

The Final Build is the last opportunity to manufacture Finished Goods (FG) and Spare Parts. Once the production line is dismantled, the cost to reconstitute it is 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, institutional knowledge is lost. 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).

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Recap: End-of-Life Management Disposition

Phase	Key Parameter	Requirement / Constraint	Action / Disposition	Documentation
LTB Sequence	Customer Orders	Must be NCNR (Non-Cancelable, Non-Returnable); based on hard PO, not forecast.	Secure component stock prior to PDN issuance.	NCNR Agreement.
Final Build	Raw Material Buffer	Mandatory 3–5% overage on BOM. No ECOs during final build.	Procure with scrap allowance.	Procurement Plan.
Service Stock	Spare Parts Quantity	Required Spares = (Active Install Base × Failure Rate) × Warranty Years + Safety Buffer.	Manufacture to cover full warranty period.	Service Stock Calculation.
Disposition (Post-LSD)	Excess Inventory	Unique Parts: 100% customer liability. Common Parts: CM absorbs/returns. WIP: Complete to FG or scrap.	Assign liability per agreement; complete or scrap WIP.	CM Agreement.
Disposition (Post-LSD)	Production Tooling	Store for 3-5 years (possible service) or destroy. If destroyed, require Certificate of Destruction.	Consign, archive, or destroy with evidence.	Certificate of Destruction (COD).