In one of my current classes we dicussed some of the metrics used to quantify software quality. One of such metrics is "defects per 1,000 lines of code." The current average in enterprise software is said to be about 1 to 3 defects per 1K lines of code. Not a whole lot until you start thinking about the millions of lines that make up the software in today’s airplanes, medical machines, your car’s break system, etc.