Indeed. You cannot release a patch for a mechanical part or a PCB.

For a PCB it’s called a rework, and it’s very common for first spins of boards to have to do one.

Also common is to patch around issues, when possible, in firmware. This is often lower cost/effort, but can’t fix everything.

There are similar kinds of fixes for purely mechanical parts. Depending on the part and problem, mechanical can be easier than a PCB rework (eg: modify a part in CAD and 3D print or get your local machine shop to do a run).

Or require a particular type of motor oil with a particular type of metal-based lubricant additive when you realise 100,000 cam shafts have shipped made of metal you’d assumed was to a higher spec but isn’t, just so the engine will make it through warranty period with insanely long service intervals.

I briefly looked at a couple used vehicles just outside of warranty and one within warranty that had literally had two oil changers in 100,000k, that’s 60,000 miles for the uninitiated.

You just release a new version. How many xbox 360s did they actually release? I think its close to a dozen iterations.

    > You cannot release a patch for a mechanical part

In NATO, this is frequent and normal. Many, many "recalls" are issued by military manfacturers, then local support staff spend X hours to replace the defective part. It is not so different from automobile recalls.

Correct. Also the economics of a mechanical patch are favourable for something in the M$ range with a fix costing in the 10k$ to 100k$ range

You can and people do.

It’s just a lot more expensive and labor intensive to apply.