PCN means product change notification; discontinuance notices address lifecycle and purchasing/delivery windows. First map affected full part numbers to BOMs, stock, inbound orders, and reorder plans, then assess assembly, electrical, software, and traceability effects. Unchanged part numbers do not eliminate review; similar numbers do not establish compatibility. Link notice receipt, technical approval, and purchasing execution continuously.
Which facts to extract first from one notice
TI's public PCN guidance lists descriptions, reasons, tracking IDs, affected products, expected impacts, qualification plans/results, samples, and expected shipping dates. It links major changes to form, fit, function, quality, and reliability. This article uses public process descriptions, not full paid standards. Check other manufacturers' contents/timing against formal notices.
| Notification Fields | Internal Correspondence | Output |
|---|---|---|
| Tracking number and complete affected part numbers | BOM, procurement code, and suffix | Affected products and version list |
| Change Description and Reason | Process, size, electrical, and software requirements | Risk items requiring evaluation |
| Samples, qualification data, and timeline | Pilot production resources and validation plan | Supplementary data and prototype arrangement |
| Shipping or Switch Conditions | Inventory, in-transit, and reorders | New/old batch identification and effective boundary |
| End-of-life procurement and delivery date | Requirements, lifespan, material preparation, and cash plan | Last procurement and replacement project node |
Retain original attachments and receipt dates when forwarding notices. Verify inclusion of the purchased full part number; some notices cover only certain packages/suffixes within a family. Prefix matches do not establish applicability throughout. Qualification plans without released results remain pending inputs, not completed passes.
Define verification scope by change object
Site, wafer, or packaging-process changes may prioritize lot identification, qualification data, and product-sensitive characteristics. Package-material/plating changes also require solderability, thermal, and cleaning assessment. Pin, dimension, and electrical changes more directly affect PCB/system design. Not every notice requires every test, but omissions need rationale and approval.
| Change Object | Items Requiring Evaluation | Possible Outputs |
|---|---|---|
| Package or Pin Structure | Pads, stencils, height, coplanarity, and tooling | Library difference, first article, and structure check |
| Electrical or Timing | Load, power supply, boundary, and interface | Comparison results under specified conditions |
| Procedure-related behavior | Startup, identification, registers, and calibration | Program compatibility and regression records |
| Materials and Manufacturing Process | Thermal limits, solderability, and reliability sensitive items | Qualification data evaluation and necessary tests |
| End of life | Usage, storage, service, and replacement schedule | Material preparation plan and substitution approval |
Replacement material is not just checking if package fits
Build itemized differences for pins/potentials, operating/absolute limits, accuracy/timing, consumption, startup, interfaces, registers, packages, and thermal restrictions. Absolute maxima are not operating points; typical performance is not guaranteed limits. Ask manufacturers or verify critical undocumented states rather than filling gaps with “compatible.”
Choose prototype conditions that expose differences. Power-device substitutes require startup, transient-load, and thermal checks; memory substitutes need interface/stress cases; connectors need mating/mechanical checks. Retain conditions, software, sample lots, and results. One passing board supports that configuration, not an entire part family or every reorder revision.
Switching between new and old batches must allow physical traceability
Technical approvals should identify permitted parts, notice IDs, product revisions, effective lots, limitations, and approvers before purchasing/production execution. Mark old/new stock and inbound materials separately to avoid undocumented mixing. Decide whether old stock remains usable, expires, or exits. If exact supplier transition dates are unavailable, define identifiable marks and receiving methods.
Synchronize reorder BOMs, substitute lists, assembly drawings, software, and tests. Purchase orders are not technical release; engineering approval does not establish completed inventory-system transitions. Batch-traceable boards need records of production lots using new parts; board-traceable projects need actual-material links to IDs. These distinguish new/old materials from other process changes during faults.
Engineering calculation for end-of-life stocking quantity
Planning example, not a forecast or purchasing recommendation: assume 18 future months at 600 boards/month, 1 device per board, plus 800 service and 200 development-verification devices. Gross demand is 18×600＋800＋200＝11800. With 1500 confirmed usable stock and 500 firm inbound, initial shortage is 11800－1500－500＝9800. Use identical part numbers and usable-state definitions throughout.
Also assess forecast errors, yield, service obligations, storage life, moisture sensitivity/solderability, cancellations, and substitute introduction dates. Safety stock needs assumptions and capital implications, not arbitrary percentages. Long-term stocking does not eliminate discontinuance risk, especially beyond storage/verification horizons; pursue substitute designs concurrently.
TI's public page describes general discontinuance arrangements and possible acceleration. Actual last-order/last-delivery dates and exceptions in specific notices govern projects. Do not copy general webpage month counts into every procurement plan or wait until the last day for prototype verification.
How to close a same-part-number process change
Engineering example: an interface device receives a packaging-process PCN without a BOM-name change. Confirm affected suffixes/new-lot identifiers, then assess plating, thermal limits, and product-sensitive performance. Build first articles with controlled stencils/profiles and inspect soldering, interfaces, and specified boundary conditions. Even if no differences appear, record tested and untested scope rather than “same part number, no testing needed.”
After approval, update notice logs, schedule old-stock depletion or dated transitions, and trace initial new-material deliveries. If first articles show nonwetting, retain original packaging, lots, and soldering records and investigate material/process factors separately. Do not assume the PCN caused failure. For source verification, connect with Authorized channel and batch traceability For package changes, review the SMT package differences.
Inputs and outputs to be received before re-order
- Original notices, complete affected part numbers, receipt dates, key milestones, and current data status
- BOM, stock, inbound, and planned-order impact lists with owners
- Difference/risk assessments, sample requirements, verification methods, and criterion sources
- Prototype/first-article results, software/process revisions, abnormalities, and approvals
- Old/new transitions, surplus disposition, delivery traceability, and follow-up results
Initial discussions need only notices and key part numbers to identify impacts. Complete controlled files and necessary verification before formal transitions. Limited trials may proceed with insufficient data, but “limited trial” is not unrestricted substitution approval. For board process records, compare the assembly review and Test Delivery Organize.
PCN and end-of-life management supplementary questions
Does a production-site-only change need a notice log?
Record receipt, applicability, and assessment conclusions. Additional testing depends on actual changes/product risk; not every site change needs identical tests.
Is a substitute still needed after placing a last-time buy?
Still assess it. Stocking depends on forecasts, storage, and later service needs. Substitution may address a different time horizon; plan both together.
Technical validation and procurement follow the same schedule
Notice logs need recipients, owners, sample plans, document completion, verification completion, purchasing decisions, and transition milestones alongside impacts. For delays, identify whether stocking or verification is affected rather than merely expediting orders. Retain before/after notices and differences when manufacturers update dates or qualification results, preventing old information from obscuring new requirements. Shared-component verification reuse needs stated conditions. Identical packages do not establish identical loads/software/environments; other products still need difference assessments after one passes. Continually check end-of-life stock usability, issues, and demand, revisiting decisions beyond original plans. Delayed substitutions require recalculated stocking/service plans and confirmation that new purchases remain within formal windows. Lifecycle management needs coordinated technical, supply, and usage updates; one last-time buy does not resolve every lifecycle risk.
Source material and applicable scope
- Texas Instruments, “Product change notification (PCN)”; webpage version not identified; checked 2026-10-17; sections: notice contents and Semiconductor product withdrawal/discontinuance. Supports TI's public notification process/fields. Actual notices govern dates/exceptions; this does not replace full paid standards.
Build a notice-to-production decision timeline
For each PCN or end-of-life notice, copy the manufacturer's notice ID, affected full part numbers, change description, effective date, sample or last-order dates and final-delivery date where stated. Map those numbers to BOM revisions, on-hand lots, open purchase orders and products still in service. The notice is not closed merely because purchasing has acknowledged the email.
- Engineering identifies what may change in form, fit, function, quality or reliability and which test evidence is needed.
- Purchasing confirms stock, supplier dates and whether an approved alternative can arrive before the next build.
- The product owner approves the new part or last-time-buy route, with a revision or controlled deviation and a switch date.
- Production records which board identifiers received old and new lots, then checks that the approved test and labeling reflect the transition.
The date fields are manufacturer- and notice-specific. Texas Instruments' PCN process is a useful example, but its timing is not a promise for other suppliers or for every notice.
Repeat-build handoff: attach the notice
Provide the manufacturer notice, affected BOM revision, inventory and next-build date. Use the repeat-build scope and project inquiry to review substitution and verification work.
