Several factors have to be considered for planning a project: time allocated, available money, human and material resources, etc. The main goal in the planning of a project is to determine a plan for organizing the project so that there is a succession of activities, which is a road determined by the rout with entrance roat and the exit roat, the rout sought to be a maximum length, the roat called Critical path. The PERT method is similar to the CPM method only that the problem is treated probabilistically because there are situations when the project planning does not know certain times of accomplishment of the activities, then it will give some probable times and will determine the critical path depending on these times.