[Someone]

agile with lowercase ‘a’ was defined for software development (https://agilemanifesto.org/), so you cannot blame it for not applying fully to hardware development.

The manifesto is extremely flexible, though (it doesn’t mention standup or fixed-length sprints, for example), so I think it can work for hardware, too, but you likely have to make the sprints longer and be more flexible in lengthening or shortening them to match reality, maybe do more documentation, etc.

I think ”half year sprints” loosely is how the Apollo program was run (https://en.wikipedia.org/wiki/List_of_Apollo_missions), certainly after Apollo 1, when they realized the schedule wasn’t the most important thing in the world.

https://en.wikipedia.org/wiki/Apollo_1#Program_recovery: “We were too 'gung-ho' about the schedule and we blocked out all of the problems we saw each day in our work. Every element of the program was in trouble and so were we.”

The dogma of Agile with a capital “A”, on the other hand, IMO, doesn’t work for anything, be it software or hardware.