You’ve probably heard the expression “five nine reliability,” which is shorthand for saying that a product, Web site, service, application, or whatever is fully functional 99.999% of the time, the equivalent of less than six minutes of downtime per year.
Most Web sites don’t need to achieve that level of reliability. However, when you’re in the business of critical infrastructure, e.g., the natural gas that people use to cook their food and heat their houses in the winter, you had better be aiming for a pretty serious uptime target.
National Grid apparently thinks otherwise. When I contacted them to find out why there have been several incidents recently when I was unable to view or pay my bill online, here’s how they responded:
Our system goes down every night between 10:30 PM and 6:30 AM for processing. During this time you cannot view bills or take care of other processes for your account like payments or paperless billing. Please try going online during the daytime to view the bill.
In other words, their Web site has planned downtime, let alone unplanned downtime, for a third of every day, so their maximum possible uptime, assuming no other outages ever occur (which, alas, is not the case), is 66.666%. That’s an awful uptime ratio. Really, really awful.
National Grid ought to fire whoever thought it was reasonable for their Web site to be down for eight hours out of every day, not to mention whoever thought it was necessary for their Web site to be down for eight hours out of every day.
![[Digg]](http://blog.kamens.us/wp-content/plugins/bookmarkify/digg.png)
![[Facebook]](http://blog.kamens.us/wp-content/plugins/bookmarkify/facebook.png)
![[Email]](http://blog.kamens.us/wp-content/plugins/bookmarkify/email.png)
About a month ago, I 
