The Institut für Fertigteiltechnik und Fertigbau Weimar e. V. (Institute of Precast Technology and Precast Construction, Weimar, registered association) has concerned itself intensively in recent years with the problem of quality assurance in the manufacturing of concrete elements on block making machines. In the context of several research projects, the most diverse technical influences and parameters were examined and technical systems were developed that permit the monitoring of the manufacturing process or the optimal adjustment of the machine parameters. The technology of the manufacturing of concrete blocks represents a very complex process that requires optimum coordination between the machine and the mixture to be processed. Very short cycle times of approx. 15 seconds and the fact that the pro - duct is demoulded immediately after compaction mean that even the tiniest error often leads to unsatisfactory results in terms of quality.