Two intervention studies in the steel industry are presented. One experimental group (El) changed from a discontinuous weekly backward (advancing) to a quicker forward (delaying) relating shift system. The second experimental group (E2) first worked in a weekly backward rotating and then in a quicker forward rotating shift system. These experimental groups and two control groups (not changing their shift system) filled out questionnaires before and ten month after the change to new shift systems in the experimental groups. In the second questionnaire study there were significant improvements of the satisfaction with the new shift systems and some significant reductions of social problems in comparison to the old shift system in the experimental groups. No significant differences were observed with regard to health effects, sleep duration, sleep disturbances, and duration of leisure time. Nevertheless after the pilot period of ten month with the new Shift systems 95% (E2) and 100% (E1) voted in favor of the new shift system. Relevance to industry - There are many reasons for changing traditional shift systems, from the employers' view and also from the workers' view. If the shift system has to be changed, it is sensible to take ergonomic recommendations for the design of shift systems into consideration to reduce the negative effects of shiftwork on well-being, sleep, family life, social life, health and performance.