The evolution of management theory over the last century has seen leaders shift from owner-managers who relied on authority to modern servant leaders who lead by example. Early managers could use strong tactics to achieve goals, but today's servant leaders must live the values they want followers to adopt. Formal management study began late in the 19th century as the Industrial Revolution increased demand for strong processes to maximize productivity and profits. Various theorists have developed improved methods since the 1800s. Management has evolved greatly over history and will continue influencing the future.