The 5-M Factors are a model called Man-Machine-Medium-Mission-Management, and are used to examine the nature of accidents in the transportation industries. It was started by T.P. Wright's Man_Machine_Environment triad at Cornell University. The 5_M incorporates a diagram of 3 intertwined circles and one all_encompassing circle. In each of the smaller circles "Man," "machine," and "medium" are placed. The large circle is labeled "Management." The space in the middle where they all meet is called "Mission," which is the objective the other four M's have in common.