This paper presents an optimization model for the problem of optimal scheduling of tamping actions on ballasted tracks. The model extends an existing one in the literature by including the unused life costs for track sections in the objective function and introducing available workforce constraints in the model. The aim is to obtain an optimal schedule for tamping actions minimizing the total cost in a finite time horizon using global optimization. The results of numerical study show that consideration of track layout in the problem leads to a significant increase in the total number of tamping actions and the amount of unused life for track sections. It is also found that it is important to use a big value for available workforce in the problem in order to reduce the total cost. The proposed model presents a more realistic solution for the studied problem than the existing work in the literature.