We address the problem of designing and planning a multi-period, multi-echelon, multicommodity logistics network with deterministic demands. This consists of making strategic and tactical decisions: opening, closing or expansion of facilities, supplier selection and definition of the products flows. We use a heuristic approach based on the linear relaxation of the original mixed integer linear problem (MILP). The main idea is to fix as many binary variables as possible with the linear relaxation coupled with rounding procedures. The number of binary variables in the resulting MILP is small enough to enable solving it with a commercial solver. We compare the computational time and the quality of the results obtained with the heuristic and the commercial solver.