The Optimum Distribution of Tasks Among Operators in a Multiman-Machine System

Abstract

To ensure that tasks are distributed among operators in a team so that none is either overloaded or underloaded, it is essential that consideration is given to the demands imposed by tasks, and to their potential modification by the manner in which the team is organised. Of primary importance are certain characteristics, or general properties of tasks, such as their complexity and organisation. Whereas the former refers to the information-processing demands imposed on the operator by each task independently, the latter refers to the inter-relationships between tasks. Two types of task organisation may be distinguished: intra-task organisation refers to the inter-relationships existing between the tasks of an individual operator, i.e. the extent to which they impose similar demands, whilst inter-task organisation is defined by the degree of interaction between team members. A series of five experiments is described in which the effects of such task characteristics on the performance of two-man teams is investigated, using simulated command, control and communication tasks, Teams are organised in either vertical or horizontal manners. In the vertical method, the total task requirement is divided into functional categories and responsibility for certain functions is assigned to each operator. The output from the first operator is the input to the second, However, in the horizontal organisation, both operators may act simultaneously since the total task demand is divided between them, and the tasks of each operator may include all the functions required in the total task. Experimental results generally favoured the horizontal organisation, but this superiority tended to diminish when intra-task organisation was low, when inter-task organisation was high, or when the high complexity of individual tasks led to an overall task complexity too high for effective time-sharing.