One of the challenges relying on computers is to recognize that they sometimes do the wrong thing. And to deal with the consequences. This story about the UK Post Office is a sad tale about the accounting software that almost put over 1,000 managers of post offices in prison for fraud. Only to find that it was a software error.
The Horizon system, developed by the Japanese company Fujitsu, was first rolled out in 1999 to some post offices to be used for a variety of tasks including accounting and stocktaking.
But from an early stage, it appeared to have significant bugs which could cause the system to misreport, sometimes involving substantial sums of money.
It was difficult for sub-postmasters to challenge errors because they were unable to access information about the software to do so.