Reply to post: I know my career hasn't been typical...

I know my career hasn't been typical...

... but I've read countless versions of this sort of thing over the years and they universally fail to address three major use cases. The first is obvious: safety critical systems. You cannot have "blame free postmortems" when actual postmortems are involved and the people doing the blaming will be the Crown Prosecution Service. This isn't just about aircraft flight control, it applies to far more mundane things like factory conveyor belt systems. Which brings me to the second category:

Systems where the "user" is simply a wetware robot who exists solely to carry out the instructions issued by the software. An early example of this (for me) was a factory making flavours for ice cream: the ingredients had to be mixed in precise quantities with precise timing and moved along a conveyor arrangement. The process could have been fully automated but (back in the '90s) that was far too expensive and retrieving some ingredients from storage wouldn't be possible with a robot even today (without rebuilding the factory).

In such cases "user feedback" usually doesn't matter. The TIM study ("Time in Motion" - remember those?) tells you how long each process takes and the potential for accidents/mistakes is obvious and can be accounted for. Feedback regarding the process itself (how about we add X before Y?) is worthless because the "users" have no conception of what they are actually doing (neither did the programmer - a guy with two PhDs dealt with that). This sort of system gets its feedback from sensors, not users, which brings me to:

Huge numbers of "computing" devices cannot be patched. The software they run when they ship is there for life. You can't (realistically) reflash a microwave or a washing machine and this has spilled over into the sexy new IoT field with the (catastrophic) addition of Agile/SCRUM/"No blame" people let loose on the code. You cannot "iterate" this sort of software. You get it right first time or you're looking at a product recall and/or market vilification.

All these analyses and methodologies seem to start with the assumption that "software" consists of FaceBook and Enterprise CRM systems. It doesn't. In fact such systems are a tiny minority. There are about 50 billion ARM chips out there and about 6 billion smartphones. What are the rest of them doing?