PCN & PDN: How to Read Discontinuation Notices and Respond

Manufacturers communicate changes and discontinuations of their components through standardised documents: the Product Change Notification (PCN) and the Product Discontinuation Notice (PDN). If you read these notices early and correctly, you gain valuable time for a structured response – ignore them, and you risk costly surprises.

PCN vs. PDN: What Is the Difference?

Both documents originate from the component manufacturer and are distributed through distributors or direct channels, but they signal different situations:

• PCN – Product Change Notification: The manufacturer informs you of an upcoming change to a component that remains orderable – for example, a die supplier change, a package modification, a new manufacturing site, or a specification update. The component stays available, but qualification testing may be necessary.
• PDN – Product Discontinuation Notice: The manufacturer announces the definitive end-of-life of a product. The PDN contains the critical cut-off dates: the Last Time Buy Date and the Last Time Ship Date.

A PCN can be the precursor to a PDN – especially when it points to declining margins or technology shifts. It is therefore worth tracking and evaluating PCNs systematically as well.

The Key Fields in a PDN

The structure varies by manufacturer, but you should check and document the following information in every PDN:

1. Affected Part Numbers: Which exact type and variant numbers are affected? Do they match your active bills of materials?
2. Last Time Buy Date (LTBD): The date until which orders will be accepted by the manufacturer (or authorised distributor). After this date, no new orders are possible.
3. Last Time Ship Date (LTSD): The date until which already-placed orders will still be delivered. Between LTBD and LTSD there is often 3–6 months of production lead time.
4. End-of-Life Date: Not always stated explicitly – often identical to the LTSD or a few weeks later.
5. Reason for Discontinuation: Provides clues about the availability of alternatives and likely market behaviour.
6. Recommended Replacements: Successor or replacement components suggested by the manufacturer – these must be qualified internally, but they are a good starting point.

Response Checklist After Receiving a PDN

1. Match the affected part numbers against all active bills of materials (including service spare parts).
2. Calculate total remaining demand until product end-of-life or the next redesign – what a solid LTB calculation looks like is covered in the dedicated article.
3. Enter the Last Time Buy Date and Last Time Ship Date in your internal ticket or ERP system and assign a responsible owner.
4. Make a decision: place a Last Time Buy, qualify an alternative, or initiate a redesign? More on the options in the article End-of-Life for Electronic Components: What a Discontinuation Really Means.
5. Research alternatives – evaluate manufacturer-recommended replacements as well as independent candidates.
6. Check delivery windows at authorised distributors and build a safety stock where appropriate.
7. For complex requirements or tight deadlines, bring in external support for sourcing discontinued components.

PCN and PDN Monitoring: How to Stay on Top

Many organisations receive PCN/PDN notices only sporadically – via distributor newsletters, direct manufacturer portals, or as PDFs in the inbox. Structured monitoring includes:

• Automatic subscriptions at authorised distributors (e.g. through their customer portals)
• Lifecycle tracking tools that continuously match bills of materials against manufacturer databases
• Regular (quarterly) manual review of critical components at NRND status
• Clear internal processes: who receives, evaluates, and escalates PDN notices?