For the writing of this diploma thesis as a default Facility, a multipurpose building was chosen. With this building, it is necessary to evaluate the final project execution time. In order for this assessment to be carried out, it is first necessary to define the list of activities according to which the project will be carried out. After defining the activity, access to the calculation of their duration is defined. To calculate the duration of the activity it is necessary to have estimated quantities, by means of norms to determine the required normative time and the number of working groups, and finally, the number of working hours in one work shift. Using this data, it is determined, most likly duration of an activity. Then the activities are linked in to a meaningful whole that results in the most likely completion time of the project. The expected copletion time of the project was defined applaying the PERT method and the predetermined most probable time. Also, the probable project completion time is determined. In the end, a critical path analisys was performed and the total working hours displayed for a more probable project execution time.