In this paper, it will be shown how information and communication technologies (ICT) act as enablers to realize changeable production systems within the German machinery and equipment industry. A cybernetic structure is proposed to design and operate systems that have to cope with a high degree of complexity due to continuously changing environment conditions. The integration of IT-Systems along the order processing of small-and-medium-sized enterprises (SME) is shown to be one of the missing links of changeable production systems in practice. A demonstration case is presented in which standardized interfaces of IT-Systems enhance real-time data exchange between the relevant planning levels of producing companies, their suppliers and customers.