5M model

Original labels

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:

• Man (people): including the physiology and psychology of those involved, as well as their performance and proficiency.
• Machine (equipment): including the design, manufacture, maintenance, reliability, performance, etc.
• Medium / measurement (environment, inspection): including weather, terrain, obstructions, lighting, etc.
• Mission (purpose): the reason these three factors are brought together.
• Management (leadership): the prevailing supervisory approach in terms of regulations, policies, procedures, and attitude involved in establishing, operating, maintaining, and decommissioning.

Expansion

These have been expanded by some to include an additional three, and are referred to as the 8 Ms:

• Material (includes raw material, consumables, and information)
• Method / mother nature (process, environment)
• Maintenance

Other uses

This is also used in more general troubleshooting or root-cause analysis, such as with the Ishikawa diagram.

References

References

1. Cusick, Stephen K.. (2012). "Commercial aviation safety". McGraw-Hill Professional.
2. Ballesteros, J.S.A.. (2016). "Improving Air Safety Through Organizational Learning: Consequences of a Technology-led Model". Routledge.
3. (3 March 2016). "Safety management systems in aviation". Routledge.
4. Bradley, Edgar. (3 November 2016). "Reliability engineering: a life cycle approach". CRC Press.
5. Weeden, Marcia M.. (1952). "Failure mode and effects analysis (FMEAs) for small business owners and non-engineers: determining and preventing what can go wrong". Quality Press.
6. Crutchfield, Nathan. (2008). "Job hazard analysis : a guide for voluntary compliance and beyond : from hazard to risk: transforming the JHA from a tool to a process". Elsevier/Butterworth-Heinemann.