Complex construction projects require appropriate planning that allows for time and cost optimization, maximization of the use of available resources and appropriate investment control. Scheduling is a complicated process, due to the uncertainties and risks associated with construction works, the paper describes the development of the scheduling method traditionally used in Poland, based on data from KNR catalogs, by using the RiskyProject Professional program. In the RiskyProject Professional program, the risk and uncertainty with reference to a specific construction project were modeled, and the calculation results were compared with the real time of the project implementation. The conclusions from the work carried out confirm that the SRA (Schedule Risk Analysis) analysis of the base schedule allows for a more faithful representation of the actual conditions of a construction project. The probability of investment realization generated on the basis of the SRA analysis may be assumed at the level of 75÷90%.