There can be no valid universal calculation system; it has to be designed and implemented taking into account the realities of the environment in which the organization is carrying out its activity and especially the internal conditions and demands of the management system. The best calculation system is obtained by putting in the balance the cost of the errors resulted from mistaken estimations and the cost of the more precise measurements.
Acknowledgements
This article is a result of the project POSDRU/6/1.5/S/63269
Fund through The Sectorial Operational Programme for Human Resources Development 2007-2013, coordinated by
Valahia University of Targoviste.