Amit Ranjan at Webyantra points to the enormous leverage that software has on our day to day lives. The consequences of bugs are usually thought of in terms of customer dissatisfaction, schedule slippages and maybe at worst a bunch of pink slips. Next time someone trivializes testing or defect fixing, make them read this:

Explosion of Ariane 5, 1996 due to “…conversion of a 64 bit integer into a 16 bit signed integer lead to an overflow…”

Loss of Mars Climate Orbiter, 1999 due to “…mix-up between pounds and kilogram….”

Mars Polar Lander, 1998 due to “…software error that mistakenly identified the vibration caused by the deployment of the lander’s legs as being caused by the vehicle touching down on the Martian surface….”

Loss of Mariner 1, 1962 due to “..period instead of comma in FORTRAN DO-Loop…”

Breakdown of AT&T’s long-distance telephone network, 1990 due to “…a single line of buggy code in a complex software upgrade implemented to speed up calling caused a ripple effect that shut down the network….”

USS Yorktown dead in the water, 1998 due to “….input and Division by ‘0’. „ X / 0 = undefined…”

MIM-104 Patriot Missile Failure, 1991 due to “…rounding error”

Shutdown of 5 nuclear reactors, 1985 due to “..use of arithmetic sum of variables instead of the square root of the sum of the squares of the variables….”

Denver International Airport, 1994 due to “…baggage handling system broke down because of numerous bugs….”

Reading this definitely made me more reverent about my own beginnings- doing Y2K fixes. I used to resent the work and thought it as 'dumb' and spent a lot of time writing automation tools instead. :-)