Most obsolescence problems are actually visibility problems
The two companion pieces in this cluster both assume you already know a part is at risk — either because a notice arrived, or because you're staring at an already-obsolete part with no documentation. But the more common failure mode happens earlier: nobody had a clear picture of which connectors across an active product line were single-sourced, high-volume, and long-lead-time all at once, so the EOL notice landed as a surprise instead of a known risk finally materializing.
A BOM risk register fixes that. It's not a complicated system — a spreadsheet is genuinely fine for most operations below a certain scale — but it needs to exist as a deliberate, periodically-reviewed document rather than living only in one engineer's memory of "oh yeah, that connector's always worried me."
What actually goes in it
A useful register tracks a handful of fields per connector line item, not an exhaustive component-level BOM export:
Part number and manufacturer — the obvious baseline.
Single-sourced or multi-sourced. If a documented, qualified second source already exists (see the site's dual-footprint and cross-compatible design guidance for how that gets built into a design in the first place), that materially changes the risk level below.
Annual/committed demand. Total remaining volume across all active products using this part — not just the next build.
Lead time (current, not catalog-quoted). Catalog lead times and actual current lead times can diverge significantly during allocation periods; track what you're actually being quoted, not what a datasheet says.
Criticality if unavailable. Does losing this part halt one product's production, several, or the whole line? A connector used across five product families is a different risk than one used on a single legacy SKU.
Known alternates identified (yes/no). Whether anyone has actually verified a replacement, not just whether one theoretically exists somewhere in a distributor catalog.
Last reviewed date. A register nobody updates is worse than no register, because it creates false confidence.
A simple scoring approach
You don't need a sophisticated weighted model to get real value here — a basic three-tier flag, reviewed honestly, beats an elaborate scoring formula nobody maintains. One workable version:
Red (act now): single-sourced, no verified alternate identified, and either high committed volume or high criticality (used across multiple active products).
Yellow (monitor): single-sourced but with a verified alternate on file, or multi-sourced but with a long/volatile lead time worth watching.
Green (low concern): genuinely multi-sourced with both alternates actively qualified and stocked, or low enough volume/criticality that a shortage would be a manageable, not urgent, problem.
The specific thresholds matter less than actually running every active connector line item through this classification at least once, since the exercise itself is usually what surfaces the 2-3 parts that were quietly a real problem the whole time.
When to actually review it
A register reviewed once a year and then forgotten doesn't do much. In practice, a few trigger events are worth tying a review to rather than relying purely on a calendar:
A new product enters the BOM — every new connector added should get scored before it goes into production, not after.
An EOL or PCN notice arrives for any part already on the register (see the companion piece on reading these notices for what to actually do with one) — this is the moment a Yellow or Green item may need to move to Red.
A distributor lead-time quote comes back meaningfully longer than the last time you checked — a real-world early warning signal that doesn't require waiting for a formal notice at all.
What to do with a Red item
This is where the rest of the cluster becomes the actual playbook rather than just reference reading:
If a manufacturer-recommended or community-known alternate exists, verify it against your actual application (mechanical fit, electrical ratings, environmental requirements) rather than assuming a datasheet-level match is sufficient.
If no clean alternate exists and the part is already discontinued or undocumented, the site's parametric identification and reverse-engineering workflow is the practical next step — measuring pitch, contact geometry, and keying to search distributor databases for a genuine match.
If the part is still active but flagged Red purely on single-source/high-criticality grounds, this is the point to proactively qualify a second source and update the register to Yellow — before a notice forces the timeline.
Note for anyone coming from a defense/aerospace background: this general practice overlaps with what's formally called DMSMS (Diminishing Manufacturing Sources and Material Shortages) management in that industry — the underlying discipline is the same, just usually run with far more process overhead than a commercial electronics shop needs. Borrowing the mindset (proactive risk tracking, not reactive scrambling) is useful even without adopting the full formal framework.
Bottom line
The register's value isn't the spreadsheet itself — it's the forcing function of actually looking at every connector on an active BOM and asking "what happens if this specific part disappears next quarter." Most of that list will come back Green or Yellow. The few that come back Red are exactly the ones worth spending an afternoon on now, rather than discovering them the hard way later.
Not sure how to score a specific connector's risk, or need a second opinion on whether an alternate you found actually qualifies? Ask the Engineer — real questions from real designs get answered.
