I'd be interested in a simple flight deck system to allow crew to absolutely know without a doubt that in the context of a displayed warning, is the associated sensor functioning correctly or not and has it been activated or not. I'm thinking of a something like a nuisance cargo smoke warning triggered on the ground by vehicle exhausts or humidity and silenced, but sinced it's latched into the FWC it reappears at 1500'. We all know it's nothing but it still requires a return to base to be certain and cancelling.