| This thesis focuses on the production planning for a work shift in an open pit mine. The planning problem is to maximize the transportation of fragmented rock during a work shift while satisfying various operational constraints.First, we present a basic model that includes the main groups of constraints. Then, we enrich this model with additional constraints on the capacity of the fleet of trucks, including an estimation, by linear inequalities, of the waiting time at the shovels.For solving the proposed linear model, we use a solver named Xpress-MP. The solution strategy is simple and, for a medium sized instance, the computational time is less than five seconds.We also develop tools for determining if, in some cases, the instance is infeasible before starting the solution process. In cases where these tools does not detect an instance infeasibility, an algorithm can be used to identify a group of constraints causing this infeasibility. This method allows the user to adjust the parameters of the instance to obtain a valid production plan.We propose a linear model that includes the main constraints encountered in the mining industry. The model includes the operational capacity of equipment, the quantity and the characteristics of the ore available at the shovels and the characteristics of the ore at the crushers. The thesis proposes a new method to include and linearize nonlinear functions that one used for estimating the waiting time of the trucks at the shovels. We use a linear model because such a model can easily be solved in a reasonable computational time. |
