Maximum Value Safety Nets

Related to my previous post about parameters in application development, I've recently been incorporating safety nets into my applications to catch those unusual data occurrences that can result in very abnormal results of calculations. Results far outside what was expected and that can have a dramatic effect on the final output of the system.

I've built in safety nets that will trap any outliers and limit them to a maximum, or minimum value. As you've guessed, these safety nets are defined at the grain of that fact to give the maximum level of control of the system.

Hindsight is a wonderful thing and I wish I'd put these in at the start as although the number of these issues that have surfaced have been small. The pain they've caused me has far outwieghed the effort to have designed them into the system in the first place.

The biggest pain has the credibility issue that these instances have caused. We'll all be familiar with the newspaper headlines about people being charged thousands of pounds by mistake (in fact there was one today.. man loses driving license for doing 383mph on a motorbike). These isolated issues, which may be 1 defect in millions of transactions, cause people to lose faith in the system. These can easily get blown out of all proportion by anyone with an axe to grind against a new system.

'If this numbers wrong, then maybe they're all wrong...'

Clearly not the case, but how many you out there have faced this situation.. Safety Nets..!