Define Safety Management System the features of the "Four pillars"

Visit the Hunt Library and conduct an article research regarding an aspect or item associated with SMS. Summarize the article, explain and correlate the relevancy of the article to the module and, of course, have the proper citation
Module objective
this module, you should be able to:

Define Safety Management System the features of the "Four pillars".
Explain the development of SMS both nationally and internationally.
Explain the role of audits and inspections within the SMS program.
Identify the various risk assessment and calculation formats used in SMS.
Discuss the various communication portals needed for a safety program.
Explain the purpose of the risk/hazard matrix and severity classifications.
Discuss the significance of proactive risk reduction.
Defend the economic costs of a proactive safety program.