"Henry Harteveldt, founder of the travel consultancy Atmosphere Research Group, said some airlines are choosing to risk outages that might cost them $20 million to $40 million rather than invest, for example, $100 million on technology upgrades. He believes investors and the general public will apply increasing pressure on airlines to avoid outages at any cost."
How much did this cost Delta? Both directly and indirectly.
How much will preventing this single point of failure cost?