Management has never been defined by a set protocol, and therefore the judgment of managers has not encompassed a set standard. Rather, the act of assessing what would make a "good" or "bad" manager has been a recent field of study in efforts to help eliminate undesirable individuals from potentially acquiring management positions. .
The importance of management is exemplified due to a worker's value being determined namely by the way they are being managed, and the value of a company being determined on how well their employees work. Management, being a discipline, is an organized body of knowledge and therefore managers should be evaluated on how well they comprehend, and execute the comprehension of that knowledge. (Drucker) To be able to have a certain criteria to follow in judging managers will enable a company to determine if an individual is actually helping a company reach their goal.
There is a huge market for testing centers and often a very gullible one, due to the high salaries of managers and companies wanting more than a resume and some references. They can be effective if the company is actually doing something different as a result of the tests (i.e. hiring people that they might have not hired before) or if management performance has actually changed for the better as a result of the testing. (Stewart 1981).
In the past managers have been appointed by such techniques as appointment committees, interviews, age, tenure, experience, relationships, performance evaluations, etc.
Traditional ways of assessing managerial potential, based on the well-founded hypothesis that a person's track record may not tell one that how they will perform when translated into a different, and possibliy more demanding position. A good solution to this is to place a canidate into a simulated version of the new position and whatch how they perform, judging them according to the criteria of effectivness which are thought to be appropriate to that position.