A method of analysis of a control part of the cyber-physical system described by a Petri net is presented in the paper. In particular, boundedness of the system is examined. Contrary to other well-known techniques, the proposed idea does not require obtaining of all place invariants, nor computation of all reachable states in the net. Therefore, it is possible to check the boundedness of a net in a more effective and efficient way, compared to the traditional, well-known methods. Furthermore, the proposed algorithm has been examined experimentally with a set of 243 benchmarks (Petri nets). The research results show the high efficiency of the proposed method, since a solution was found even for such nets where popular techniques were not able to analyse boundedness of the system. Finally, the presented idea is illustrated by a case-study real-life example.