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7 Let’s Start with Some Serious “Do Nots”!
Pythias includes risks associated with the possibility of sudden non-linear behaviour,
such as the risk of self-reinforcing global warming or of the instability of the West
Antarctic ice sheet, with far more disastrous consequences than those of gradual
climate change. Static liquefaction failures would belong to this category.
Pandora’s Box is characterized by both uncertainty in the probability of occurrence
and extent of damage (only presumptions) coupled with high persistency.
Cassandra is characterized by a relatively lengthy delay between the triggering event
and the occurrence of damage. If the time interval were shorter, the regulatory authorities would certainly intervene because the risks would be clearly located in the intolerable area. Many tailings dams are in this category.
Medusa refers to the potential for public mobilization. This risk class is only of
interest if there is a particularly large gap between lay risk perceptions and expert
risk analysis findings. Poorly made risk assessments and poorly disciplined approach
may transform tailings dams risks into this category.
Sometimes risk assessors experience difficulties (if they do not, then they are doing
something wrong) when people balk at wide range of events scenarios, trying to bias
the studies toward what they believe are “credible” events in terms of probability p
and consequences C (losses). The censoring they propose is generally double:
• reducing averages and
• narrowing ranges to say −10 to +15%.
That censoring is of course completely arbitrarily-selected and based on “experience”. That experience is unfortunately often short term and localized, thus useless
or misleading.
For example, while assessing risk on mountainous mines’ (tailings) pipelines and
roads we consider a maximum scenario which includes full loss of the pipe and the
road along it. Of course we look at local topography and other parameters before
introducing such an event at a given location (Oboni and Oboni 2018).
That maximum scenario generally encounters fierce hostility from the client or the
professionals in charge of operations. We have seen that reaction occurring both in
North and South America. They consider that scenario as excessive, actually “incredible” based on their “experience and gut feeling”, and they bring plenty of reasons
for that “incredibility”.
Yet these accidents occur and generate risks. They come loaded with potential fatalities and image/reputational consequences.
So, those accidents are not only occurring, but they occur in many countries around the
world with a rate that oftentimes places the generated risks in the societally intolerable
realm (see Chap. 13). As a result, those accidents are unfortunately not “incredible”
and show that “experience and gut feeling” are not good advisors when assessing
risks.
7 Let’s Start with Some Serious “Do Nots”!
Pythias includes risks associated with the possibility of sudden non-linear behaviour,
such as the risk of self-reinforcing global warming or of the instability of the West
Antarctic ice sheet, with far more disastrous consequences than those of gradual
climate change. Static liquefaction failures would belong to this category.
Pandora’s Box is characterized by both uncertainty in the probability of occurrence
and extent of damage (only presumptions) coupled with high persistency.
Cassandra is characterized by a relatively lengthy delay between the triggering event
and the occurrence of damage. If the time interval were shorter, the regulatory authorities would certainly intervene because the risks would be clearly located in the intolerable area. Many tailings dams are in this category.
Medusa refers to the potential for public mobilization. This risk class is only of
interest if there is a particularly large gap between lay risk perceptions and expert
risk analysis findings. Poorly made risk assessments and poorly disciplined approach
may transform tailings dams risks into this category.
Sometimes risk assessors experience difficulties (if they do not, then they are doing
something wrong) when people balk at wide range of events scenarios, trying to bias
the studies toward what they believe are “credible” events in terms of probability p
and consequences C (losses). The censoring they propose is generally double:
• reducing averages and
• narrowing ranges to say −10 to +15%.
That censoring is of course completely arbitrarily-selected and based on “experience”. That experience is unfortunately often short term and localized, thus useless
or misleading.
For example, while assessing risk on mountainous mines’ (tailings) pipelines and
roads we consider a maximum scenario which includes full loss of the pipe and the
road along it. Of course we look at local topography and other parameters before
introducing such an event at a given location (Oboni and Oboni 2018).
That maximum scenario generally encounters fierce hostility from the client or the
professionals in charge of operations. We have seen that reaction occurring both in
North and South America. They consider that scenario as excessive, actually “incredible” based on their “experience and gut feeling”, and they bring plenty of reasons
for that “incredibility”.
Yet these accidents occur and generate risks. They come loaded with potential fatalities and image/reputational consequences.
So, those accidents are not only occurring, but they occur in many countries around the
world with a rate that oftentimes places the generated risks in the societally intolerable
realm (see Chap. 13). As a result, those accidents are unfortunately not “incredible”
and show that “experience and gut feeling” are not good advisors when assessing
risks.