Two empirical uncertain models for project scheduling problem

The project scheduling problem with uncertain activity durations is considered, and two types of models for uncertain project scheduling problems are established according to different management requirements. These models are transformed to their crisp forms, which may be solved by classical optimization methods. For the models that could not be transformed to their crisp forms, an uncertain simulation is employed to approximate uncertain functions. Finally, two numerical examples are given to illustrate the usefulness of proposed models.