Elevators generally breakdown at random times and for different reasons elevated maintenance contractors must have trained service personnel to provide routine and emergency service Shanon elevator Hong Kong has $200$ service personnel to maintain $1000$ elevators suppose that Shannon has received a contract to maintain an additional $1000$ elevators do you expect that Shannon will need to double service personnel why oh why not escalators and elevators use quite different technology and parts but many clients operate both escalators and elevators are there any economies of scope for a contractor to maintain both escalators and the elevators