Static function allocation: when a functions allocated to the system, and those allocated to the operator, remain the same over the operation duration.
Dynamic function allocation: Usually referred to as adaptive automation, where the functions are allocated depending (hopefully) on the estimated workload of the operator. How the automation is allocated is usually determined by the designer of the automation who would determine the trigger which would best moderate operator workload, and result in optimal system performance.
This is sometimes known as adaptable automation: This usually refers to automation where the operator has the authority to invoke automation during the operation.
The above automation ‘types’ are convenient and useful. However there are a number of layered strategies on how functions are allocated in an operator-machine system which are not satisfactorily captured in this nomenclature.