The 3 most important things to know if you're managing half a million employees

ISS is a Danish company based in Copenhagen which specialises in logistics services, such as cleaning, catering, and building management. With 518,000 employees, ISS is the fourth-largest employer in the world, and looks after landmarks like the Eiffel Tower in Paris and the Sagrada Familia in Barcelona.  In Britain, it cleans the trains on the London Underground London and the Carlsberg brewery in Northampton, among the others. One year after going public on the stock market in Copenhagen, th...