The prevailing pressure for economic efficiency forces companies to continuously assess the effectiveness of all areas. This increasingly affects personnel development: In hardly any company is it transparent what contribution it makes to success, as the precise measurement of hard values in this field is challenging. Wolfram von Schneyder develops a reference model that documents the processes and activities of personnel development. Based on this, he derives a system of key performance indicators that illustrates value creation. This allows for the verification of the effects achieved with the personnel development budget and the forecasting of the impacts of a changed budget. For practitioners, the book provides a reference for implementing their own system; researchers will find an overview of the research conducted so far, along with a presentation of more than 200 key performance indicators.