An Integer Programming Model of Reinvestment Strategy Based Project Portfolio Selection and Scheduling with Constrained Resource

Selecting an appropriate series of projects among numerous candidates and assigning start and finish time for every selected project under the constraints of limited resource does matter in the project management. With the introduction of annual budget and time value of capital, the proposed problem becomes more complex. In this paper, an integer programming model is proposed and constructed to model the situation of selecting and scheduling suitable project portfolio at the same time with constrained resource, in which reinvestment strategy is also applied in the process. In reality, annual budget is time-dependent, so it is necessary to take time value of capital into account during the modeling process. The use of reinvestment strategy means that the profit earned by accomplished projects is put into the resource pool to finance more projects to be selected and executed in order to make the total profit of project portfolio maximal. During the modeling progress, others constraints are also considered, like project interrelationship, to represent closely practical situations.