Read the lifecycle status like a buyer
Every manufacturer publishes a lifecycle vocabulary — learn to read it before you need it. ACTIVE means recommended for new designs. NRND (not recommended for new designs) is the status buyers misread most: the part is still orderable, but the manufacturer has stopped promoting it, which usually means the clock is ticking. LIFEBUY means a last-time-buy window is open with published last-order and last-ship dates. OBSOLETE means it is gone. TI’s public policy shows what a disciplined withdrawal looks like: its discontinuance process complies with J-STD-048, provides “a longer lead time than the industry standard,” and allows 12 months for the last order plus 6 more months for final delivery — and TI states it makes an effort “not [to] obsolete products out of convenience”. When you see LIFEBUY, the first question is not “how much” but “what are the exact dates” — everything else follows from the calendar. Watch for the quiet signals too: a part that disappears from the manufacturer’s parametric search, loses its evaluation board, or stops appearing in new reference designs is often on its way to NRND long before any notice is published. Distributors’ end-of-life flags and rising minimum order quantities tell the same story from the market side — by the time the formal notice arrives, the informed buyers have already run their checks.
The three-step lifecycle check
Run this check across the BOM twice a year, and every time a PCN lands. Step 1 — classify every line: lifecycle status, sole-source versus multi-source, and qualification sensitivity. Automotive, medical, and industrial-temperature parts are the hardest to re-qualify, so they get priority — a commodity resistor and a qualified MCU are not the same risk class. Score each line on two axes: how hard it is to replace (sole-source, custom, or qualification-sensitive scores high) and how much warning you are likely to get (commodity parts give months; custom parts give years, but only if someone is watching). Step 2 — check what the manufacturer actually commits to: ST, for example, certifies selected devices under a 10-year longevity program — a minimum 10-year availability commitment that explicitly includes the notification period under its standard end-of-life notification policy. A part inside a longevity program and a part with no commitment are different risks even when both show ACTIVE today. Step 3 — assign an owner and a review cadence per risk class: critical lines get a named owner and a quarterly look; everything else gets the twice-yearly sweep. A plan without an owner is a document, not a process.
- Step 1 — classify: lifecycle status, sole-source exposure, and qualification sensitivity per BOM line.
- Step 2 — check commitments: a part inside a manufacturer longevity program is a different risk than one with no commitment.
- Step 3 — assign ownership: named owner and quarterly review for critical lines, twice-yearly sweep for the rest.
The last-time-buy decision table
A last-time buy is a bet with four inputs — price the bet honestly before placing it. Input 1 — demand forecast: only a defensible, written forecast justifies a lifetime quantity; “we might need them” is not a forecast. Input 2 — storage and handling: moisture-sensitive parts need dry storage and floor-life discipline, and a last-time buy without a storage plan just moves the obsolescence problem into your warehouse. Input 3 — alternate status: if a qualified alternate already exists, the last-time buy is a bridge, not a lifetime commitment — size it as a bridge. Input 4 — cash and terms: the money is committed the day the order is placed, usually non-cancelable and non-returnable. Buy the lifetime quantity only when the forecast is defensible, storage is disciplined, and no qualified alternate exists; in every other case, buy a bridge quantity and put the effort into qualifying the alternate.
- Lifetime quantity only when: defensible forecast + disciplined storage + no qualified alternate.
- Bridge quantity when: an alternate is close to qualified — fund the qualification, not the warehouse.
- Walk away from the lifetime buy when: the forecast is a guess, or storage discipline cannot be guaranteed.
A live case: Murata’s nine-series withdrawal
This is what the check is for, happening right now. In September 2026, multiple trade outlets reported that Murata notified customers of the withdrawal of selected part numbers across nine MLCC series — GRM, GRJ, GRT, GXM, GXT, GCM, GCJ, GCG, and ZRA — with a customer response deadline of December 31, 2027, final orders by March 31, 2028, and final shipment on March 31, 2029 (SemiMedia, September 14, 2026; corroborated by MK and Yonhap Infomax). Note the framing carefully: this is trade-media reporting of a customer notification, not a murata.com page — confirm your exact ordering code with your channel in writing. The lesson for the lifecycle check: a withdrawal program with a multi-year tail still collides with an allocation market, and the buyers who fare best are the ones who ran step 1 of the check before the notice arrived. Our MLCC shortage buyer’s guide walks through the three-step part-number check for exactly this situation.
Keep evidence
Record lifecycle notices, forecast assumptions, supplier quotes, and engineering approvals so future decisions have context. Pair this with date-code evidence and timestamped availability for the lots you actually buy — when a last-time buy arrives two years later, the date code is what proves it is the lot you qualified. When the plan calls for a lifetime buy or a qualified alternate, put the full ordering codes and date-code requirements on one RFQ: our RFQ workspace captures part number, manufacturer, package, date code, target price, and quantity per line, plus a notes field for the substitution policy. The evidence trail starts with the request, not the receiving dock.
Build response paths before you need them
For every critical line, pre-define the response paths while supply is still available: approved alternates reviewed through the alternative-component review — never approved from a database match alone — redesign options with their cost and lead time, and second-source candidates already sampled. A part like STM32F103C8T6 or NE555DR on a production BOM deserves this treatment long before any notice arrives. And when a part is already discontinued, document the decision trail the way MC3672 does, recording the end-of-life notice and the manufacturer-recommended replacements. The teams that handle EOL notices calmly are the ones that wrote down why they chose each alternate months earlier — the teams scrambling are the ones deciding under a last-time-buy deadline.
Frequently asked questions
Quick answers to the questions buyers ask most about obsolescence planning.
- Q: When should obsolescence planning start? A: Before any notice arrives — run the three-step lifecycle check twice a year, prioritizing sole-source and qualification-sensitive lines.
- Q: A part just went EOL — what’s the first move? A: Get the exact last-order and last-ship dates in writing, document the decision trail, and check the manufacturer’s recommended replacements.
- Q: Should I place a last-time buy? A: Only with a defensible forecast and a storage plan — otherwise buy a bridge quantity and put the effort into qualifying the alternate.
- Q: NRND vs EOL — what’s the difference? A: NRND is still orderable but not recommended for new designs; EOL carries published last dates. Treat NRND as the warning and EOL as the deadline.