A Methodology for Predicting Crew Workload in New Weapon Systems

The Army currently is evaluating the feasibility of single-crewmember operation of a multipurpose, lightweight helicopter, designated the LHX. To determine if a single operator can perform the LHX scout and attack missions, 29 mission segments were analyzed for excessive workload. The mission segments were divided into flight control, support, and mission functions; the functions were divided into performance elements (tasks) and were positioned on mission segment timelines. For each performance element, the man-machine interface was identified and estimates of the visual, auditory, cognitive, and psychomotor components of workload were assigned. The mission/task/workload data were used to build one- and two-crewmember computer models designed to predict total workload and to identify overloads in each mission segment. Two baseline analyses were conducted to predict workload under low-automation conditions for one- and two-crewmember LHX configurations. In addition, iterative analyses were conducted to predict the reduction in workload associated with each of 26 individual automation options and 16 combinations of options. The methodology provides a systematic means of predicting human operator workload in advance of system design.