Engineering psychology is a vast area of study which includes a lot of factors to be studied. Engineering psychologists learn the principles of ergonomic design and scientific selection. In order to perform human operation the ergonomics optimizes machine designs and the ultimate goal is to select and train people for this purpose. It might sound complex but with relevant education and training individuals could perform exceptionally well.
An engineering psychologist is hired by companies to make their brands appealing to the targeted customers.
via : Psychology School Guide