Product or Process Change Notice
The part may remain active, but a controlled product or manufacturing attribute is changing.
Electronic component lifecycle guide
PCN vs PDN vs NRND vs EOL vs Last-Time Buy
These terms do not mean the same thing. A PCN announces a change. A PDN announces discontinuance. NRND warns against a new design. EOL describes product retirement. Last-Time Buy is the final order window set by the supplier.
FirstMatch the exact orderable MPN.
ThenClassify change, status, or withdrawal.
Before the date closesQualify, redesign, or plan supply.
Read the supplier's current notice, affected-parts list, revision, dates, and commercial conditions.
The short answer
Separate the Notice, the Status, and the Deadline
PCN and PDN are communications. NRND, EOL, and obsolete are lifecycle conditions or labels. LTB and LTS are commercial milestones. Mixing these categories can cause an unqualified change, a rushed redesign, or the wrong final-buy quantity.
Product Discontinuance Notice
The supplier is withdrawing the listed product and normally provides final-order information.
Not Recommended for New Designs
Existing users may still be supported, but a new platform should evaluate an active alternative.
End of Life
The product is moving through retirement or has reached the end of manufacturer supply.
Last-Time Buy
The final date or window for submitting an order under the discontinuance process.
Last-Time Ship
The latest planned shipment milestone for accepted final orders, subject to notice terms.
| Term | What changed? | Immediate action |
|---|---|---|
| PCN | A product, process, material, site, test flow, firmware, marking, specification, or related controlled attribute. | Check exact MPN scope, effectivity, identification method, evidence, and application-specific qualification. |
| PDN | The listed product is being discontinued. | Capture LTB/LTS dates, order conditions, remaining demand, replacement path, and support exposure. |
| NRND | The supplier's recommendation for new designs has changed. | Do not release into a new platform without an active alternative review or a documented lifecycle exception. |
| EOL | The product is entering or completing retirement. | Plan the end of manufacturer supply; do not infer support from distributor stock alone. |
| LTB | The final-order window is closing. | Lock demand assumptions, confirm commercial conditions, submit early, and obtain written acceptance. |
| LTS | The final shipment period is closing. | Plan cash, receiving, storage, shelf-life, lot controls, and production use of accepted final supply. |
Lifecycle map
PCN Can Happen During Active Life; PDN Starts the Supply Exit
There is no universal sequence for every manufacturer, but this map shows the operational relationship. The actual product page and current supplier notice always control.
Active
Supported for existing and new designs under the supplier's policy.
PCN Event
A controlled change may occur while the product stays active.
NRND
Continue existing-use review, but avoid a new design without exception.
PDN / EOL
Withdrawal is announced and dated work begins.
LTB / LTS
Final order and shipment milestones close.
Obsolete
Manufacturer production has ended under its lifecycle definition.
Important: a PCN is not automatically an EOL notice, and NRND is not automatically obsolete. Some suppliers use different labels or combine PCN/EOL portals, so verify the notice title, revision, affected MPN attachment, and dated terms.
Classify before acting
Use One Question to Find the Right Response Path
The same purchasing response does not fit every notice. Start by identifying whether the event is a change, a design-status warning, or a supply withdrawal.
Run the PCN path
Map exact affected items, assess technical and quality impact, request evidence or samples, and control the introduction date.
Run the NRND path
Separate legacy use from the new platform, compare active alternatives, and require an exception before design release.
Run the PDN/EOL path
Calendar LTB/LTS, decide bridge-buy versus redesign, validate the replacement, and obtain accepted-order evidence.
PCN review
A Change Notice Is Not Proof of Drop-In Safety
A PCN should tell you what changed, why it changed, which orderable part numbers are affected, when changed material may first arrive, and what qualification support is available. That information begins the customer assessment; it does not replace it.
The risk depends on the application. A die change can affect electrical distributions, timing, leakage, thermal behavior, or errata. An assembly-site change can affect traceability and package evidence. A plating or mold-compound change can affect soldering, moisture sensitivity, corrosion, or compliance records.
- Compare the exact ordering suffix, package, grade, and approved AVL entry.
- Capture the publication date, notice revision, response deadline, and earliest changed-material date.
- Define the lot, date-code, marking, or revision method that identifies changed material.
- Decide whether document review, samples, A/B testing, PPAP, revalidation, or customer approval is required.
Confirm every suffix used in the BOM, approved vendor list, alternate list, and production location.
Identify product, material, fab, assembly, test, firmware, marking, or documentation changes.
Determine the earliest changed material could arrive and whether segregation is required.
Treat the supplier statement as evidence for review, not a substitute for system-level risk assessment.
Review methods, samples, conditions, results, traceability, and gaps against your obligations.
Name the authorized owner for acknowledgement, questions, samples, qualification, and closure.
First 48 hours
Turn a Notice Into Named, Dated Work
The immediate goal is not to finish every qualification or buy. It is to stop uncertainty from spreading and protect the supplier deadline.
Verify
Confirm manufacturer source, notice number, revision, issue date, and current status.
Map
Match exact affected MPNs to BOMs, AVL entries, inventory, orders, sites, and customer programs.
Classify
Separate change qualification from lifecycle planning and commercial deadlines.
Protect
Calendar response, EFSD, LTB, LTS, sample, forecast, and approval dates with margin.
Assign
Name engineering, quality, purchasing, program, and manufacturing owners with one closure owner.
Do not plan to the last calendar day. Final orders can require forecast review, internal authorization, MOQ alignment, NCNR approval, supplier acceptance, and payment or credit clearance before the stated cutoff.
Risk-based qualification
Match the PCN Response to the Real Application Risk
“Form, fit, and function unchanged” may support a decision, but it does not define the customer's validation duty. Consider the change type and the product's safety, reliability, regulatory, and field obligations.
Documented review
Possible when the change is well bounded and has no relevant effect in the application.
- Exact MPN mapping
- Specification revision review
- Evidence and approval record
Sample and process checks
Useful when material, site, package, marking, or process differences could affect manufacturing or receiving.
- Lot or date-code segregation
- Assembly or incoming trial
- Targeted functional testing
Controlled requalification
Needed when safety, regulation, high reliability, software behavior, precision, RF, thermal, or customer approvals could be affected.
- Formal qualification plan
- Regression and reliability evidence
- Customer or PPAP approval
Last-Time Buy planning
Buy Against the Support Obligation, Not Fear
An LTB is often NCNR and can create years of cash, storage, traceability, shelf-life, and obsolescence exposure. Model several demand scenarios before committing.
Practical calculation
Production demand + service and warranty demand + qualification/build allowance + yield and scrap allowance − usable traceable inventory − confirmed inbound supply
Approved forecast through final production, ramp-down, and contractual supply commitments.
Repair, warranty, depot, installed-base, regulatory, and field support obligations.
Historical scrap, line setup, repair use, qualification builds, and BOM quantity.
Correct MPN, traceable source, condition, allocation, storage, date code, and shelf-life suitability.
After the final buy
Inventory governance continues after receipt.
Plan protective packaging, lot and date-code traceability, ESD and moisture-sensitive handling, storage monitoring, cycle counts, allocation by program, and an end-of-use disposition. A mathematically sufficient quantity is not usable supply if its condition and identity cannot be protected.
Replacement qualification
“Recommended Replacement” Does Not Mean “Qualified Equivalent”
A supplier recommendation may mean pin-compatible, functionally similar, or simply the nearest portfolio option. Approve substitution only after the actual system differences are understood.
Ordering identity
Full MPN, package, temperature grade, qualification, finish, packing, revision, and no-connect behavior.
Electrical and timing
Operating conditions, absolute maximums, distributions, interface timing, analog behavior, derating, and thermal path.
Software and firmware
Registers, defaults, boot mode, calibration, security, diagnostics, errata, and production-test behavior.
Manufacturing
Footprint, MSL, reflow, finish, programming, fixture, tape-and-reel, marking, and traceability.
Reliability and approvals
Automotive, medical, safety, EMC, environmental, PPAP, end-customer, and regulated-product requirements.
Approved disposition
Record direct substitution, controlled running change, new board revision, restricted use, or no replacement.
Cross-functional ownership
A Lifecycle Notice Is Not a Purchasing-Only Task
One person should own closure, but the decision needs evidence from the functions that carry technical, quality, schedule, commercial, and manufacturing risk.
Engineering
Classify technical impact, compare revisions, define tests, evaluate alternates, and approve disposition.
Quality
Assess evidence, traceability, qualification, regulated-product duties, PPAP, and customer approval.
Purchasing
Confirm notice scope, dates, channel, samples, terms, final orders, and written supplier acknowledgement.
Program
Own schedule, support horizon, customer communication, escalation, funding, and risk acceptance.
Manufacturing
Control lot introduction, process checks, programming, fixtures, storage, traceability, and cutover.
Buyer and RFQ checklist
Send the Details That Protect the Decision
Use this list when requesting lifecycle status, change evidence, replacement support, or a final-buy quotation.
Exact manufacturer and complete orderable MPN, including suffix.
Manufacturer notice number, title, revision, issue date, and source link.
Affected BOM, AVL, programs, locations, quantities, and open orders.
PCN change scope, effectivity/EFSD, identification method, and supporting data.
PDN/EOL LTB date, LTS date, MOQ, NCNR, allocation, and acceptance process.
Application, grade, environment, service life, annual volume, and approval needs.
Replacement comparison basis: pin, function, qualification, software, and package.
Required traceability, date code, packaging, inspection, records, and test evidence.
Final quantity and delivery schedule acknowledged in writing by the supplier.
Final BOM/AVL disposition and change-control record updated for future buyers.
Lifecycle sourcing review
Need to Review a PCN, PDN, Replacement, or Final-Buy Requirement?
Send the exact MPN, notice revision, quantity, annual usage, support horizon, target date, destination, acceptable alternatives, and evidence requirements. YURUNOX can organize the sourcing response around the actual offered stock and agreed review scope.
Quick answers
Frequently Asked Questions
The supplier's current policy and notice always control when its labels, dates, or commercial terms differ.
Is a PCN the same as an EOL notice?
No. A PCN generally announces a product or process change and can apply while a component remains active. A PDN or EOL notice announces withdrawal or discontinuance. Read the title, affected MPN list, revision, effectivity, and any LTB/LTS dates.
What is the difference between PDN and EOL?
PDN commonly means Product Discontinuance Notice, while EOL means End of Life. Manufacturers may use the terms differently. For action, rely on the actual notice: exact affected parts, final-order date, final-ship date, replacement status, and order terms.
Does NRND mean a component is obsolete?
No. NRND means the supplier does not recommend the part for a new design. It may remain available for existing designs, but a new platform should evaluate an active alternative before design release.
Can I still buy a part after the Last-Time Buy date?
Do not plan on manufacturer acceptance after the LTB date. Distribution or aftermarket stock may remain, but it can have different source, condition, traceability, warranty, date-code, authenticity, and price risks.
What should be included in a Last-Time Buy calculation?
Include production through the support horizon, service and warranty demand, qualification/build allowance, and realistic yield and scrap. Subtract only usable, traceable internal stock and confirmed inbound. Then apply MOQ, packaging, delivery, storage, and supplier terms.
Is a supplier-recommended replacement automatically drop-in compatible?
No. Verify complete MPN, package, pinout, operating conditions, timing, firmware, thermal behavior, manufacturing requirements, reliability, and customer qualification obligations before substitution.
Who should respond to a PCN?
The response should be cross-functional. Engineering assesses technical impact; quality evaluates evidence and approval duties; purchasing manages supplier communication; program management owns schedule and escalation; manufacturing controls introduction. One accountable owner should close the record.
How often should lifecycle status be checked?
Check during part selection, schematic release, design freeze, NPI, and regular sustaining reviews. Subscribe to manufacturer notices for used components. Increase review frequency for sole-source, high-reliability, regulated, or long-life programs.
Manufacturer references
Check the Current Supplier Policy and Actual Notice
These primary manufacturer sources explain representative lifecycle and notification practices. A timing example from one supplier must not be treated as a universal rule.
TIProduct lifecycle definitions for Active, NRND, Last Time Buy, and Obsolete.
Analog DevicesPCN and PDN policy, notice fields, and supplier-specific timing policy.
MicrochipProduct/process change notifications, notice stages, and EFSD explanation.
MicrochipEnd-of-life policy and transition considerations.
onsemiExample discontinuance notice with LTB/LTS dates and final-order conditions.
InfineonProduct change notification overview and standards references.