Obsolescence management: what to do when electronics are discontinued
Machines, aircraft systems and plants run for decades. The electronic components inside them often disappear after a few years. Obsolescence management is the discipline of seeing this coming – and having a plan when it happens anyway.
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What obsolescence means in electronics
A component or assembly is obsolete when it can no longer be bought from the original manufacturer under its original specification. In electronics this happens fast: semiconductor product lines are optimised for consumer markets, and a chip that is designed into an industrial controller may be discontinued long before the controller reaches the end of its life.
The international standard IEC 62402 describes obsolescence management as a structured process across the whole life cycle of a product. In aerospace and defence the term DMSMS (Diminishing Manufacturing Sources and Material Shortages) is common.
The terms you will see
| Term | Meaning |
|---|---|
| PCN | Product Change Notification – the manufacturer announces a change, e.g. new die, new package or new production site |
| NRND | Not Recommended for New Designs – still available, but the end is in sight |
| EOL | End of Life – the manufacturer announces that production will stop |
| LTB | Last-Time Buy – the final date for ordering, usually 6 to 12 months after the EOL notice |
| LTS | Last-Time Ship – the final delivery date |
| FFF | Form, Fit, Function – a replacement that is mechanically and electrically interchangeable |
Reactive or proactive
Reactive obsolescence management starts when a part is no longer available. The options are then limited and expensive: searching broker stock, buying risky parts or redesigning under time pressure.
Proactive obsolescence management monitors the bill of materials continuously, rates each component by risk and starts measures before the last-time buy. For a small or medium company, a pragmatic version is enough:
- Keep the BOM of every product that is still in service, with manufacturer part numbers.
- Check the life-cycle status of the critical parts at least once a year.
- Decide per part: last-time buy, qualify an alternative, or plan a redesign.
- Keep the design data of every board – Gerber, BOM, schematic – in a current, readable format.
The options when a part or board is gone
| Option | When it makes sense | Risk |
|---|---|---|
| Last-time buy and storage | Demand is known and the part stores well | Capital tied up, storage conditions, ageing |
| Broker and grey market | Very small quantities, short-term | Counterfeits, unclear storage history |
| Authorised aftermarket | Original die or licensed reproduction exists | Higher price, limited range |
| Drop-in replacement | A pin- and function-compatible part exists | Small electrical differences must be checked |
| Board redesign | Several parts are obsolete or no replacement exists | Engineering effort, possibly requalification |
| Rebuild from sample | The whole board is no longer available and no data exists | Depends on complexity and firmware |
The most common blind spot: missing design data
Many obsolescence plans focus on components and forget the board itself. When the board supplier closes, the Gerber files often go with it. Then even a simple part change becomes a reverse-engineering project. Securing the manufacturing data of your critical boards is the cheapest obsolescence measure there is.
If you have boards in service without data, send us a sample and the parts list. We check what can be recovered and give you a fixed price.
Questions
What is the difference between EOL and LTB?
EOL is the announcement that a product will be discontinued. LTB is the last date on which you can place an order, usually several months after the EOL notice.
How do I know if my components are obsolete?
Look up the manufacturer part numbers on the manufacturer's site or in a component database; the life-cycle status is shown as active, NRND, EOL or obsolete. We do this as part of every assessment.
Is a redesign always necessary?
No. Often a single drop-in replacement solves the problem. A redesign makes sense when several parts are affected or when the board should be modernised at the same time.