[simne]

IBM TOS, probably most reliable what I seen. For example my first leased line have TOS 99.9% (14 hours of downtime per month), and for most desktops and smartphones I don't seen any TOS at all (only guaranteed change if I found evidence of manufacturer defect within guarantee term, usually 1-3 years, depend on manufacturer).

But leased line and smartphones are not regulated in my country, and as I said before, controllers for smart buildings are regulated (sure, not all, but some functions are very strictly regulated, for example because of this exists huge proposal of second hand equipment, because near impossible to install it into other place after left spare because of upgrade).