This B11 Technical Report provides a means to identify hazards associated with a particular machine or system when used as intended, and provides a procedure to estimate, evaluate, and reduce the risks of harm to individuals associated with these hazards under the various conditions of use of that machine or system. 

ANSI B11.TR3-2000 Risk Assessment and Risk Reduction - A Guideline to Estimate, Evaluate, and Reduce Risks Associated with Machine Tools.

B11.0.TR3 Risk Assessment Matrix

In this model the risk terms are correlated to the level ofg risk reduction required.

Risk: the combination of the probability of occurrence of harm and severity of that harm.

In allegato Estratto ANSI B.11.TR3-2000 Risk estimation