Assumption - for whatever reason, you don't want visual signals, the easiest/most obvious approach.
Just about any of the ESP wifi devices could read a set of inputs and send a message to another. Keep safety out of the game, though. The audible message can, of course, be only heard through headsets, for example.
In one of my early jobs, the supervisor used red - machine failure, yellow - need attention, critical, green - need attention, not critical, and white - out of raw material, IIRC, flags to do what you want. Machines were a line of metal lathes and other metalworking equipment; super could look out office window and see at a glance what was what. Super cheap, failproof.