What is a common risk to be considered when analyzing an operation? 1- Human behavior 2- Machinery failure 3- Natural Hazards

Thanks 

It is human behavior since no one can expect what human behave can be, while machine has ON-OFF and catalog, and natural can gives us some alarm before disasters but human doesn't  

If you mean by operation , the operation of plant or factory machinery , you consider the risks of machinery breakdown and / or failure .

kind regards ,

The common risk to be considered when analyzing operation involving human behavior, machinery failure and natural hazards is the potential to cause incident that may cause loss of life, injury, near miss, property damage and reputation impact. Human behavior could lead to unsafe act, machinery failure might be caused by unsafe condition and natural hazards are caused by mother nature such as earthquake, floods, heat, etc.. etc.

all of above can do but focus on Human behavior

Thank you for your invitation. I support my colleagues answer & looking forward to new answer.

Thanks for invitation,

I do believe that all three factors has to be considered, when we are analyzing for the "operational risk". 

Human Behavior is more critical than other two factors.

Thank you for your kind invitation

(The correct answer (1 

human behavior..............

Depending on the situation, all three would need to be assessed carefully.