Quantitative Risk Analysis
This calculates the cost of impact for each risk, in priority order of the
risks. So if the risk was to happen, what is the estimated cost in terms of effort,
materials, equipment, and tools through direct and indirect costs (to other tasks)?
For the first risk - escape plot discovery:
- The cost of trap or tunnel discovery was almost always catastrophic in that
typically the project was over. The costs were extremely high in terms of effort
put in, thousands of man-hours, and quantity of shoring materials. Once a tunnel
was detected, none of these would be recovered and everything was lost.
- The cost of not containing nosy ferrets could be measured in the loss of output
of clandestine activities measured in effort put in, hundreds of man-hours, and
the materials for the activity. For example, discovery of one of the escape factories
(manufacturing items for the escape) would have a significant impact on the project.
- The cost of tunnel sand discovery was very serious as it would likely increase
the intensity of searches for the tunnel and hence put the project at risk. It
is likely the ferrets would not cease looking for the tunnel.
For the second risk - dangers with tunnel engineering:
- The cost of collapsing tunnels was disastrous and could be measured in terms
of lost lives and abandonment of the tunnel. The tunnels were long (330 feet/100 m)
and very deep (30 feet/9 m). One cubic metre was approximately 1 ton,
so there was a significant weight above the tunnel.
- The cost of bad air saturated in carbon dioxide could also be measured in
terms of serious injury or loss of lives.