Nowadays the application mode of the tool and rule systems of the lean philosophy plays a relevant role in the competitiveness of companies. Basically, the advantage is realized by reduction of logistics wastes. In our opinion integration of the more important lean tools (VSM, SMED, Kanban) with simulation modeling may be necessary in many cases in order to increase efficiency in manufacturing/production processes. The paper presents these possibilities. In addition, it outlines research directions in connection with the examined areas.