The debate whether management is an art or science is still going strong. So, is it art or science? To me, it is both. Getting things done through people is an art as much as it is a science. Planning how to get things done and executing those plans efficiently are in the domain of science. Communicating your plans and motivating people behind those plans are in the domain of art. John Reh in his article on Management at About.com, has this to say,

Management is both art and science. It is the art of making people more effective than they would have been without you. The science is in how you do that. There are four basic pillars: plan, organize, direct, and monitor.

Four workers can make 6 units in an eight-hour shift without a manager. If I hire you to manage them and they still make 6 units a day, what is the benefit to my business of having hired you? On the other hand, if they now make 8 units per day, you, the manager, have value.