Principles for modelling function allocation

Automation is the key element in safety, reliability of industrial processes. Selecting the right type and level of automation requires careful consideration of how to allocate tasks between operators and automation. This is important in order that the joint system, human and machine as seen together, perform in the intended manner. The Halden Reactor Project is currently engaged in a project to study this topic, with an emphasis on maximizing the operator's ability to maintain control and handle unexpected events. Functional models can be used to study this in a process control environment, because they explicitly describe the functions that must be provided by the process or the operator. This paper describes how functional modelling of the joint system can be used to provide a basis for how functions should be allocated. (C) 2000 Academic Press.