Risk analysis.  It sounds obscure, but we do it all the time.  Decide to cross the street, and you're performing risk analysis.  It also turns out that we're pretty bad at analyzing risk.   This explains, in part, how so many people get hurt crossing the road.  A lot of research has gone into figuring out why we do such a poor job, and it turns out there are lots of reasons.  Sometimes you don't have all the information. Sometimes you have the information, and ignore it.  And many times you don't understand the potential consequences of different courses of action.   The bottom line is that risk analysis and risk management often go awry.

In the world of enterprise networks, we are under a barrage of information about risk.  Every day, we hear news about some security problems lurking on our networks, and we're urged to fix them immediately.  When we deal with that information, we're performing risk analysis.   When we run out and install every security patch we read about, we're performing poor risk analysis.

Every major software vendor maintains a "security alert" mailing list, and if you're a conscientious network manager, you subscribe to the ones most relevant to you.  But  dozens of other mailing lists and web sites are also dedicated to making security patch information available in a timely way.  Network World runs one, edited by Jason Meserve.   Last weekend, I learned about a business, Threat Focus, selling customized security alerts.

One factor which contributes to poor risk analysis is having too much awareness of a problem.  Get hypersensitized about an issue, like security threats, and you're bound to react in a way disproportionate and uncalled for by the real facts of the situation.  We're not just inundated with security information: we're overwhelmed by it.  This sets us up to make poor decisions.

The reality of today's software development life cycle is that full production releases don't come out bug-free.   What does this mean for quickly made, poorly tested, security patches?  They're as likely to have bugs, if not more so.  Microsoft, because it releases so many patches, has hit the news with reports of updates that made things worse, but they're not alone.  A few weeks ago, Apple introduced 10.2.4, a bug-and-security patch to their OS X operating system.  People who installed it suddenly discovered problems with their power management and PPP stacks.  Anyone can make these errors.