The intention to find an optimal way of employee performance appraisal led to the development of a number of methods. Methods differ in terms of their laboriousness, time demands, costs and usability, e.g. for the purposes of reward of employees subject to the appraisal. A significant criterion for the distinction of methods and their suitability for specific situations is time or whether the method is aimed at the evaluating of work already carried out or the identification of future results.