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Showing posts with the label bug

Avoiding Death By Exposure

There's no such thing as a small bug. Customers, be they people or businesses, do not measure Software bugs in metres, feet or miles or kilograms. They use measures like time wasted, life-lost and money.  Take a recent bug from Facebook . It affected thousands, maybe millions of customers and the bottom line of companies (seemingly) unconnected with Facebook such as Spotify, Tik-Tok and SoundCloud, and probably countless smaller companies. So why did the journalist seem to think it was small? Too often we judge the systems we create by how likely they are to fail, given our narrow view of the world. A better measure is our exposure when the systems fail . The exposure for Facebook is a greater motivation for other companies to disentangle themselves from Facebook's SDK, or promote a rival platform. It doesn't matter if our bug is one tiny assumption or one character out of place, if it stops a million people from using or buying an app then it's a huge bug. 

Dealing With Bugs Using Impossible Tests.

“Muggins! 2 for 15. My points!” My son shouts in my face. I frown and re-examine my cards, sure enough, I’ve missed a card combination. I scramble for a response… “Err... ACC Rule 10 sub-section 1 part (b) states I have to be informed prior to the game that the rule is in operation!” He’s not impressed, But sounding confident is my only hope here. I think the inclusion of the rule details has made him think twice about arguing. (It's the only rule I know off by heart, and it's a lifesaver. I might even get it tattooed on my arm.) A typical cribbage board and pegs, to help with scoring. For the uninitiated, we were playing Cribbage. An old English card game, now popular around the world. Cribbage has an interesting system of scoring, that you progressively learn the more you play. The Muggins rule my son referred to is an optional rule whereby if you underscore your hand the opponent can claim those points. As such it's become a small obsession of mine to lea

As near as damn it.

It's 1982 and there's a bull market in the western stock exchanges. After being in the doldrums for 6 years the Dow Jones Industrial Average index is climbing steeply. In London, the FTSE 100  index is also witnessing a steady climb, despite the ongoing war in the South Atlantic. The rise in share prices also leads to an increase in the popularity and prominence of these stock 'indices', the algorithmically derived snapshots of leading stock prices, frequently, used as an indicator of overall market health. At that time a relatively small North American exchange decides to institute its own new index, allowing investors to discern, at a glance, the state of the market. The Vancouver Stock Exchange creates its index at an arbitrary 1000.0 starting value. The index value is then recalculated thousands of times a day as transactions are processed through the exchange. Fast forward to late 1983, western markets have continued to boom, stimulating sustained increa

Learning from the Boeing 787's broken software.

Earlier this year Boeing 787 maintenance engineers were given some new instructions by the FAA (The US government's: Federal Aviation Authority). They were informed that if the airplane's electrical generators were left running for 248 days, they would enter the fail-safe mode.  In plain English: they will stop producing electrical power. This short video looks into why that might be and how this information can help us to test our software. The FAA directive is available on their website . A Guardian article: Boeing 787 bug could cause 'loss of control' on Dreamliner