Our common interest with our customers is that our solution should not only bring proper functioning, but economical result as well. The appropriate technical solution itself is not enough, it is very important to investigate it in the functioning economical environment. Return On Investment (ROI) calculation is made by us on our planed and delivered solutions to give the most important information to economical decision-makers. The great engineering work is for nothing, if the customer cannot earn the price of the equipment. The base of the ROI is the estimated cash flow in the future. Besides the project, every increment of the completed solution must be taken into account, the wider view, as decreasing wage cost, energy cost, increasing production efficiency, or the credit- or capital costs. Accordig to these, a realistic picture can be found about the return time of the project.