Due to customer-specific requirements that often change on short notice and vary tremendously, machine and plant manufacturers have to refactor their de-sign processes and control software, especially for operator interfaces. Opera-tor skills are crucial to operating complex systems, especially in case of a read-justment for new products or in case of a fault and the subsequent restart of the machine or plant. The paper introduces the variability of human-machine-interface (HMI) software in relation to the variability of control software, generalizing from the application example of a lab-sized demonstrator. Primarily the manual mode is focused, used to cope with errors and prepare a machine restart after an error by manipulating selected mechanical elements. The result of this paper are prerequisites and a first step to improve the de-sign of both HMI and control software towards a holistic, modular approach instead of just trying to couple both on a very low level.     «

Due to customer-specific requirements that often change on short notice and vary tremendously, machine and plant manufacturers have to refactor their de-sign processes and control software, especially for operator interfaces. Opera-tor skills are crucial to operating complex systems, especially in case of a read-justment for new products or in case of a fault and the subsequent restart of the machine or plant. The paper introduces the variability of human-machine-interface (HMI) software in rela...     »