Harmonization simulation model for managing several stochastic projects

A highly complicated project management system including several simultaneously realized PERT-COST type network projects, is considered. The projects are of different importance and significance; for each project its corresponding priority index is pre-given. The total budget at the project management disposal to carry out all the projects, is limited. Given for each project its priority value, the problem is to determine optimal budget assignments and optimal due dates of accomplishing each project, to maximize the weighted sum of the projects' utilities. The problem centers on maximizing the system's utility by implementing the harmonization model for each single project, which has been outlined in our previous publication [Math. Comput. Simul. (2002)]. Thus, the paper under consideration is an essential extension of that publication. The system's harmonization model comprises two levels. At the upper level a high-speed lookover search algorithm is implemented, together with a partial harmonization model to determine the projects' reliability values. At the lower level a linear programming model is imbedded under certain assumptions.