Constantly increasing variety of products and customer-specific requirements lead to more complex assembly lines in the shop floors. These new demands require novel systems and technologies such as flexible assembly lines, track and trace systems or assistive systems. In this paper, supporting systems on the physical level are analyzed and in particular robot assistance systems with respect to their safety aspects are discussed. Moreover, the current standards and guidelines in the field of robot safety and their development focus are presented. It is intended to provide a comprehensive overview of what role safety actually plays with assistance systems and how ongoing research may affect it in future.