In most of the threads here, an inhouse movement is frequently trumpeted as one of the attributes to look out for when considering the purchase of a new watch.
I was wondering what exactly constitutes an inhouse movement. Certain calibers are marketed as "fully developed inhouse". Others are "derived/based off XX movement eg Piguet, Lemania, ETA etc".
Would movements in the latter category be considered "partially inhouse"?
Thinking a bit deeper, I also considered the following scenarioes.
1) The subsecond dial of an ETA movement is shifted from the 6 o'clock position to 9 o'clock.
2) A watch brands grafts its proprietary chronograph movement onto a base ETA caliber.
3) Gear transmission mechanism of an ETA movement is replaced by
a) A different combination of gears constructed using some revolutionary new alloy
b) A fusee-chain system
4) An additional mainspring barrel is somehow squeezed into an ETA caliber to improve power reserve
Would any of the above be deviant enough to be considered as an "inhouse movement", or would they merely be classified as ETA-derived calibers?