The OMNIUM technique, presented here, takes the transitory course of the waste heat supply and heat demand into account and was concertedly developed for the use in the sectors small and medium-scale industry, trade and consumption on a small scale and was translated into a software programme. In the paper, the diagram of an industrial plant and the functional objective aimed at are described. After that, the optimization problem is elucidated and an initial step to a solution is formulated, which is followed by a discussion on the results.