A different modelling approach for modelling of hydraulic systems is presented in this paper. The modelling approach deals with how to obtain adequate mathematical models of the most common hydraulic elements, which are often used in process industries. Partial models should be suitable for behaviour simulation of the complete hydraulic system, for simulation of hydraulic process control applications, for supervision of hydraulic processes, and for educational purposes. All partial models, model of the pump, model of the pipeline, model of the tank, and model of the control valve, are connected logically and properly connected in a MATLAB/Simulink environment and form the mathematical model of the desired hydraulic system. The difference between the classical and presented approach is explained where non-linear and linearized models of all hydraulic elements tanks are derived. Two hydraulic processes are simulated and results show the potential of the presented modelling approach. The proposed hydraulic modelling approach was used in Bachelor and Master Study Programmes in the scope of students' individual work as seminar or project work. The model and real process measurements gave students a proper insight of modelling problems, design and selection issues of equipment and examples of good engineering practice. Positive students' feedback was towards understanding the underlying physics of the developed theoretic models in connection to real process behaviour and measurements, which is mostly missing when dealing with classic modelling and simulation courses.