In the design of some systems, the circumstance may require a determination as to whether a giver information input or processing function can best be performed by an individual or by some physical components of a system. In the consideration of human factors, also, in the design of equipment, facilities, and other physical items that people use, there are certain basic stages or processes that typically have to be carried out. The main purpose of this paper is study fundamental man-machine system assumptions in Human Factors Engineering. Therefore, this paper will deal with certain human factors that may be relevant to the design consideration that relate to human information - receiving and processing functions