End-of-life (EOL)
End-of-life (EOL) marks the point at which a supplier discontinues a part, normally announced through an EOL or product change notification (PCN) that sets a last-time-buy deadline and a final ship date. The buyer then has three options: place a last-time buy, redesign to an available part, or find an alternate or aftermarket source, each with a different cash, risk, and timeline profile.
Examples
Bridge buy versus redesign: An MCU at $1.85 gets a PCN with six months' notice. Remaining demand is 40,000 a year for eight years: a $592,000 last-time buy, plus roughly 12% a year in carrying cost. The team instead buys an 18-month bridge (60,000 units, $111,000) and funds a $180,000 redesign to a current-generation part.
When the buy is the only option: A medical device maker receives a PCN on a pressure sensor. Substituting requires a nine-month requalification and a regulatory filing, longer than the buy window, so the company orders 2.5 years of demand and starts the redesign in parallel.
Definition
The underlying problem is a lifecycle mismatch. Many electronic components live 3 to 7 years in a supplier's catalog, while the products they go into (industrial, medical, aerospace, defense) must be built and serviced for 15 or more. Every long-lived product will outlive parts of its BOM; the only question is whether the team learns this from routine monitoring or from a PCN with a 90-day fuse.
The economics run on three numbers: remaining lifetime demand, carrying cost, and requalification cost. A last-time buy converts supply risk into inventory risk (cash tied up, shelf life, the chance demand never materializes), and the stock behaves like safety stock with no replenishment behind it. A redesign costs engineering hours plus an engineering change order and requalification, which in regulated industries can take longer than the buy window itself.
Mature teams treat obsolescence as risk management rather than firefighting: lifecycle status checked at design time during new product introduction, sole-sourced parts flagged, PCN feeds monitored. Direct-materials teams use platforms like LightSource to keep BOM and supplier data current, so an EOL notice maps to affected assemblies and spend in minutes rather than days.
Frequently asked questions
What does end-of-life mean for a component?
End-of-life (EOL) marks the point at which a supplier discontinues a part, normally announced through an EOL or product change notification (PCN) that sets a last-time-buy deadline and a final ship date. From that point the buyer has three options: place a last-time buy, redesign to an available part, or find an alternate or aftermarket source.
Why do components go end-of-life while products still need them?
The underlying problem is a lifecycle mismatch. Many electronic components live 3 to 7 years in a supplier's catalog, while the products they go into, in industrial, medical, aerospace, and defense markets, must be built and serviced for 15 or more. Every long-lived product will outlive parts of its BOM; the only question is whether the team learns this from routine monitoring or from a PCN with a 90-day fuse.
How do you decide between a last-time buy and a redesign?
The economics run on three numbers: remaining lifetime demand, carrying cost, and requalification cost. In one case, covering eight years of demand for an EOL microcontroller meant a $592,000 last-time buy plus roughly 12% a year in carrying cost, so the team bought an 18-month bridge for $111,000 and funded a $180,000 redesign to a current-generation part instead.
What are the risks of a last-time buy?
A last-time buy converts supply risk into inventory risk: cash tied up, shelf life, and the chance the forecasted demand never materializes. The stock behaves like safety stock with no replenishment behind it, so sizing the buy against realistic remaining demand matters more than the unit price.
How do mature teams manage component obsolescence?
Mature teams treat obsolescence as risk management rather than firefighting: lifecycle status checked at design time during new product introduction, sole-sourced parts flagged, and PCN feeds monitored continuously. In regulated industries the redesign path can take longer than the buy window itself, as one medical device maker found when a substitute sensor needed a nine-month requalification, forcing a 2.5-year buy while the redesign ran in parallel.