Often the real risk isn’t the part it’s that no one remembers how it works.
Obsolescence in legacy electronics is often talked about in terms of parts no longer being available. Take the PLCC (Plastic Leaded Chip Carrier) package once a common standard for ICs, it’s steadily disappearing from the supply chain as manufacturers move on to newer technologies.
This disappearance creates obvious hardware headaches which are often surmountable. But a subtler, less discussed challenge is waiting in the wings to scupper you plans and that’s the loss of knowledge.
Why was this PLCC chip used? Were there special design decisions or was a firmware change made sometime after the original design? Often much of this information isn’t documented, it exists only in the memories of engineers who may no longer be around.
When this tribal knowledge fades, even simple fixes can become puzzles. The risk isn’t just that the part is obsolete it’s that no one truly understands how the system works anymore.
How much of your legacy system’s operation depends on knowledge held only in someone’s head. Recognising the knowledge gap is the first step, but bridging it takes ongoing effort.
🩺 Document early and often. Capture design decisions and workarounds while they’re fresh.
🩺 Build a living knowledge base and create processes that enable documentation to be accessible and up to date.
🩺 Foster knowledge sharing by encouraging collaboration and mentorship across teams.
🩺 Plan for obsolescence early, consider component lifecycles and knowledge retention together.
🩺 Use tools to capture context, employ software and version control that store design history.
By embedding these habits into your engineering culture, you protect not just your parts but the understanding behind them, reducing risk when obsolescence inevitably strikes.
