The field troops are the great operational commands that will be disposed on the combat zone of the land seat of the war. Every one of the field troops are formed by one or more divisions and every one of the divisions are formed by one or more brigades. The logistics support to these great operational commands is performed by the logistics basis, situated in the administration zone, and by the logistics groups, ahead groups and back groups, and logistics battalions, located in the combat zone. In comparison with the civilian society, the final clients are the troops disposed in the combat zone. The logistics basis are the plants, the logistics groups are the distribution centers and the battalions are the retail allocations. To provide the routes from one facility to another, the available military transport resources and the civilian´s one, that may be mobilized, must be used. This work introduces a methodology to be followed in optimization studies of logistics support of the field troops, that tries to obtain the minimization of the transport resources requirements to perform the supply of the troops, acting particularly to obtain the best solution in order to optimize the number and location of ahead and back logistics groups. The most important phases of the location process are to use made by the user functions, in Excel spreadsheet, and Geographic Information Systems to pre-select the cities that are able to receive a logistic group, and to solve a mathematical model by the use of mixed integer linear programming, to model this facility location problem.