Geoscience Reference
In-Depth Information
10-day labor strike at the ports of Los Angeles and Long Beach had such an impact
on some retailers in 2002 that it took 6 months before supply chains fully recovered
(Reid and Gorman
2012
). In response some retailers reduced their reliance on one
port and one set of shipping routes, to where they now utilize multiple shipping
routes and multiple ports to ensure that product flows will not be totally disrupted
by one event. In Sacramento, CA, a fire started by an arsonist destroyed a railroad
trestle in 2007. Trains that normally used this route had to detour more than 100
miles until the trestle was replaced (Peterson and Church
2008
). In exerting a
level of control and force, a drug cartel in 2013 bombed 18 electrical stations in
Michoacan, one of the largest states in Mexico (Casey
2013
). This event caused a
blackout that affected more than half a million people for 15 h. As a final example of
intentional disruption, snipers in April 2013 opened fire on a substation supplying
power to Silicon Valley, California, and knocked out 17 giant transformers, nearly
bringing the entire area to a complete blackout. U.S. Officials have stated that this
was the most significant incident in domestic terrorism involving the grid that has
ever occurred. In an unreported U.S. government analysis, researchers found that
knocking nine key substations out of 55,000 substations on a scorching summer day
could result in a coast-to-coast blackout (Smith
2014
) and it is believe that protecting
100 key substations would be enough to mitigate such an attack. This gives credence
to addressing the question of what is critical to protect. Overall, addressing such
potential risks when designing and operating a system of facilities may lead to more
resilient and efficient systems.
Facilities and associated transport networks are key elements in any production,
supply, and service system. Traditional modeling approaches for facility location
problems are based upon the assumption that systems will operate as designed.
Virtually all modern textbooks on modeling production and supply systems ignore
the problem of disruption when optimizing the location of a set of facilities. Church
et al. (
2004
) demonstrated that a given deployment of facility resources, although
optimal, could be significantly disrupted in service efficiency, while other close-to-
optimal configurations were relatively resilient when subject to the same level of
disruption. This work and the work of Snyder and Daskin (
2005
) were instrumental
in establishing a need to handle facility reliability and vulnerability explicitly.
Because of this there has been an increased interest in modeling the fragility of
networks and facility systems over a wide range of possible events from natural
disasters to intentional strikes.
Research in facility disruption is new and evolving. There are three major
problems of interest. The first one is: how much impact can be expected? This
problem involves the search for the most critical elements of a system, that is, those
facilities which when removed from operation impact the system the most. The
second important question is: how can such impacts be averted? One way of averting
a crisis may be to fortify facilities against disaster. This may mean something simple
like providing backup generators for power or providing enough security that it will
ward off a would-be attacker. It could also mean moving the facility to a nearby site
that is less vulnerable to something like flooding. The third main question is: how
might facilities be configured so that the resulting system is both efficient in service
