Before any dancers, set designers, or stage hands ever hear about a performance, (also called a ballet), it begins as an idea in the mind of a choreographer or a producer. If that person has the will, he or she will go out and get together a small group of people who will take on the many tasks that must be accomplished before the dancers even hear about the ballet.
There will be a producer, who oversees and organizes the performance right from the start. Then the producer will hire directors, choreographers, conductors, and sometimes even composers to work on the ballet. The producer will also take care of things such as booking the theatre, (which sometimes must be done years in advance), and making sure there is enough money to pay for the whole performance. Sometimes producers even have to pay the money themselves.
When the plan is in place and the "machine" is already working, then it is time to get the dancers.