5M model


The 5M model is a troubleshooting and risk-management model used for aviation safety.
Based on T.P. Wright's original work on the man-machine-environment triad at Cornell University, the 5M model incorporates a diagram of 3 interlocking circles and one all-encompassing circle. The smaller circles are labeled Man, Machine, and Medium; the intersecting space in the middle, where they all meet, is labeled Mission; while the larger circle is labeled Management:
These have been expanded by some to include an additional three, and are referred to as the 8 Ms:
This is also used in more general troubleshooting or root-cause analysis, such as with the Ishikawa diagram.