This study aims to deal with a more realistic combined problem of project scheduling and material ordering. The goal is to minimize the total material holding and ordering costs by determining the starting time of activities along with material ordering schedules subject to some constraints. The problem is first mathematically modelled. Then a hybrid simulated annealing and genetic algorithm is proposed to solve it. In addition, some experiments are designed and the Taguchi method is employed to both tune the parameters of the proposed algorithm and to evaluate its performance. The results of the performance analysis show the efficiency of the proposed methodology.