To predict system performance, understanding what affects operator performance and productivity is important. This notion was tested in a LEGO experiment including 40 students. After introducing changes in cognitive automation e.g. assembly instructions and material façade, operator performance and productivity was increased. The aggregated results give an indication of how cognitive automation affects the operators’ initial assembly performance. Industrial studies are needed to ensure observed trends and to further study the impact of cognitive automation characteristics. The trends however point toward that the perception of cognitive support has an impact on the final assembly.