Sustainability in lean production systems arises when the relevant lean principles are addressed by preferably all stakeholders in the context of permanent improvement processes. For this purpose a skills development of all employees is necessary, even for managers, as they convey the CIP position by their people skills and set an example. If this succeeds, improvement processes will develop into a sustainable learning process, which in turn serves as a self-reinforcing factor for the further development of staff skills. An approach to skills development and to the corresponding leadership system for improvement processes is presented and supported by preliminary results of an empirical study.