Human-Machine-Interfaces are with no doubt one of the constitutive parts of an automation system. However, it is not till recently that they have received appropriate attention. It is because of a major concern about aspects related to maintenance, safety, achieve operator awareness, etc has been gained. Even there are in the market software solutions that allow for the design of efficient and complex interaction systems, it is not widespread the use of a rational design of the overall interface system, especially for large scale systems where the monitoring and supervision systems may include hundreds of interfacing screens. It is on this respect hat this communication provides an example of such development also by showing how to include the automation level operational modes into the interfacing system. Another important aspect is how the human operator can enter the control loop in different ways, and such interaction needs to be considered as an integral part of the automation procedure as well as the communication of the automation device.In this paper the application of design and operational modes guidelines in automation are presented inside an educational flexible manufacturing system case study.