The main aim of this paper is to point out the possibility of utilizing Petri net-based approaches at solving different kinds of problems. Place/transition Petri nets (P/T PN) are utilized here to model the problems and to find the succession(s) of steps leading to their solving. The steps are conditioned either by knowledge based on experience or by a group of rules, constraints, limitations, etc., determined (or created) in dependence on the kind and character of the actual problem in question. The reachability tree (RT) and/or reachability graph (RG) corresponding to the P/T PN-based model help to decide on the feasible solutions. To illustrate the soundness of the proposed approach the simple example as well as the case study from the area of flexible manufacturing systems are introduced.