The free market economy comes to the life of the people and creates the new structure of the work relationships between the investors and builders. One of the most important thing of the investment and construction project is the meeting of the target date. The delays in the implementation of this project entail the material and image losses. But the building is a complex process, many factors such as delivery delays, adverse weather conditions, the correcting of low quality works, machinery and mechanisms breakdowns influence on it. During the planning stage it is unknown which of these situations may arise in the implementation process and disrupt the work schedule. That is why building projects require the strongest time control. This article presents one of the best ways to control the building process, which is named Program Evaluation and Review Technique (PERT). Although there were mentioned other variations of the time control methods, such as Graphical Evaluation and Review Technique (GERT) and method of the statistic modeling (Monte Carlo), the advantages of PERT and disadvantages of them are presented. It allows to control the expectancy of the erection and the probability of the project completion in time. This means that it allows manager to control the activity time of the project. The example of the PERT usage is represented with the comparison between the controlled project and the non-controlled project.