Design flaws in tightly coupled systems that cause error
recovery procedures to induce further errors under select conditions.
Examples include the electrical cascade failures in the U.S. power grid,
[WSCC96] telephone system cascade failures causing widespread long
distance service outages,
[Pekarske90] and inter-system cascades such as
power failures bringing down telephone switches required to bring back up
Complexity: Only cursory examination of select cascade
failures has been completed, but initial indications are that the complexity
of creating a cascade failure varies with the situation. In systems
operating at or near capacity, cascade failures are easily induced and must
be actively prevented or they occur accidentally.
As systems move further away from being tightly coupled and
near capacity, cascade failures become for more difficult to accomplish. No
general mathematical results have been published to date, but it appears
that analyzing cascade failures is at least as complex as fully analyzing
the networks in which the cascades are to be created, and this is known for
many different sorts of networks.