A part on my BOM just reached end-of-life. What do I actually do?
Reviewed · ICBOMS sourcing desk, Shenzhen
You have four routes, and they are not interchangeable: place a last-time-buy while the part is still in production, buy residual and surplus stock after production stops, cross-reference to a compatible part, or redesign. Which one applies depends on two facts you can establish quickly — whether the manufacturer has actually stopped, and whether the device is application-specific. Commodity logic, memory, analog and MCU lines usually cross-reference; programmed or application-specific devices usually do not, and for those the choice is between stock that exists now and a redesign you should cost early.
First, read the notice properly
A product change or discontinuance notice tells you which of three states you are in, and the response differs for each. NRND means the part is still manufactured but not recommended for new designs — supply is generally still reliable, which makes this the cheapest moment to place a last-time-buy, because the order is an ordinary order rather than a market search. Last-time-buy means a final order date has been published; after it passes, the quantity already in distribution is the entire remaining supply. End-of-life means production has stopped.
The most common expensive mistake is treating all three as one status. NRND is a buying opportunity. Last-time-buy is a deadline. End-of-life is a search problem. Only the middle one is free to solve.
Second, decide whether this part can be replaced by another
This is a design question, and it turns on whether the part is application-specific. For commodity MCU, memory, logic, analog and discrete lines, pin-compatible or functionally equivalent parts from another manufacturer frequently exist, and the industry has done this swap for decades. For a programmed device, an FPGA with a specific configuration, or something carrying calibration or firmware, a part-number-equivalent substitute can still be functionally wrong.
Where a substitute exists, the parameters that constrain the design decide — package and pinout, supply voltage, timing, temperature grade, and anything the firmware depends on. A cross-reference proposed without those parameters stated is a guess, not a cross-reference.
Third, treat the residual market as finite
After production stops, availability thins unevenly. The same base part number can be findable in one package or temperature grade long after another has disappeared, and it generally thins further with time. Two consequences follow: search the exact variant rather than the family, and start before the line is critical, because the economics of sourcing an obsolete part are best in the years immediately after end-of-life and get worse.
A workable default sequence
- Confirm the real state of the part from the manufacturer notice — NRND, last-time-buy, or end-of-life.
- If it is NRND or approaching a last-time-buy date, estimate lifetime consumption and place the order. This is the only route that is a normal purchase.
- If production has stopped, search the exact variant across residual, surplus and independent stock, and screen before quoting.
- In parallel, get a cross-reference analysis with the matched parameters stated, and decide whether the substitute is acceptable to the design owner.
- Cost the redesign early even if you do not choose it — the number tells you how much sourcing headroom you actually have.
Put this to work on your list
Send the part numbers or the whole BOM. Each line comes back with what can be sourced, its condition, and the cross-references where they exist — then the lines ship together.