FWIW,
I believe one needs to ask and then define what they are trying to protect.
There are many scenerios to consider. You can add all the protection, indications, whatever
and still trash the work, cause damage, or even personal injury.
The first step to safety is to invision it. The next step is to address the concern and provide protection
if even possible. Even redundantcy is not 100 %.
One way, is to avoid the problem in the first place. One can calulate HP requirements and
know before hand approx capabilites of a machine. Lots of research has been done in this area
over the years and most manufactures use the same basis for calculating stuff.
In industry evaluation is done from many different viewpoints. BUT........................
In industry it's all in terms of money / cost vrs investment ..............and that my friend is a fact!
Even loss of life is in terms of dollars in evaluations.
RICH