Why do we need controllers?

This video by the Institute of Management Accounting and Control of WHU - Otto Beisheim School of Management illustrates why companies need controllers. Controlling is about assuring management rationality.

The Institute of Management Accounting and Control of WHU - Otto Beisheim School of Management is headed by Prof. Dr. Utz Schäffer and Prof. Dr. Dr. h.c. Jürgen Weber.