Role of Security Guards in manufacturing industries

What are the main responsibilities of Security guards in food manufacturing industries? How can they asses the risk in factory surrounding? If anyone has the format for risk analysis and mitigation plan please share.

Generally speaking, they maintain the traffic flow. The QA department must do the risk analysis. 

I have found much success using the Search Function on the right hand side at the top of the forums to each question.  Please consider looking for each question you have, rather than asking it anew.