The quality of preparations carried out before building work commences has a significant impact on the smooth running and overall financial costs of a construction project. The use of construction machinery, which is crucial with regard to the efficiency of the construction process, plays an important role. In building construction, the machines in question are mainly tower cranes. The paper presents a new method for assessing the utilisation of tower cranes over time during the construction of reinforced concrete monolithic structures. The method, which contributes to the efficient utilisation of such cranes, is based on a mathematical simulation model that predicts the work cycles of a tower crane during a work shift when work is being performed on individual construction sub-processes. Construction sub-processes are analysed in detail with regard to the service provided to them by a tower crane. Data can also be obtained from binding construction schedules and boundary conditions, which in every case are for a specific executed construction project. The simulation model of the work of tower cranes has been developed for use in software applications. The created application expands the possibilities of smart construction site design in a digital environment and can also be used directly from an internet browser.