Integrated planning of project scheduling and material procurement considering the environmental impacts

Concurrent planning of project scheduling and material procurement has been addressed in this paper aiming to facilitate more efficient execution of projects. Both all-unit and incremental discount strategies, as the most commonly purchase incentives suggested by vendors, are taken into consideration to procure the materials from. On the other hand, it is advisable to deal with the side effects of a civil project, in particular, as the societies have been concentrating on the environmental issues, as well as the execution methods planning within the last years. Thus, a mixed-integer programming model is proposed to minimize the project costs, in addition to the environmental impacts. Two distinctive meta-heuristics, calibrated by the Taguchi method, are considered to solve the problem with different sizes. Finally, the applicability and efficiency of the solution methods is tested in terms of appropriate multi-objective comparison measures.