This paper proposes a multi-mode project scheduling model considering renewable resources, capital constraints, and discounted cash flows. By assigning different execution modes to the activities, the project's net present value (NPV) is maximised based on various cash flow models. The research introduces three event-based cash flow models. In two of these models, cash payments are made at the beginning and end of the activity, respectively, while in the third model, payments occur at regular intervals from the start to the conclusion of the activities. A deterministic method, a heuristic method, and a metaheuristic genetic algorithm are developed to address the problem at hand. A case study examines projects from the Sarkhun and Qeshm Gas Refinery in Iran to implement the proposed models. Data from ten projects are analysed and tested in real dimensions. Computational results indicate that the metaheuristic method achieves a higher NPV compared to the heuristic method.
DarvishNezhad et al. (Thu,) studied this question.