Abstract
The introduction of autonomous shipping as a new transport form is about to start. Defining exactly what situations the autonomous ship must be able to handle, here called the "operational envelope" is obviously important. This will be the basis for assigning responsibilities to humans or automation, for designing the human-automation interface and for testing and approval of the automation systems. There are various ways to define the operational envelope and the associated automation or human executed tasks. The importance is to refer to the awareness of a situation and to give the perception of an event with respect to time and condition, and the system behavior, actual and future. It will address the human factors by detail plans for a situation and automation awareness. It will give an understanding between automation and human role, give user experiences and usability of the solutions. An operational envelope main purpose is to describing the characteristics of a proposed system. It is used to communicate the quantitative and qualitative system characteristics to all stakeholders. This paper will examine the general requirements to the operational envelope and the description of the associated tasks and will look at some methods that can be used. It will be built on experiences from the different transport modes, as well as from the literature.