Optimisation of vehicle schedule with time windows is discussed in this paper. The problem is based on the description and data of a real-life problem. Simulation-based optimisation is used in the search of an optimal solution in this paper. A simulation model is developed for the reviewed vehicles scheduling problem. Two scenarios of optimisation are described. The first scenario involves the use of OptQuest software for the optimisation. In the second scenario, the optimisation uses an evolutionary algorithm and preliminary analysis of the problem complexity. Fitness landscape analysis methods are proposed to enhance vehicle schedule optimisation. The fitness landscape analysis is performed for the vehicle scheduling problem with time windows. The procedure of simulation-based fitness landscape analysis is described.