Risk Analysis

Risk analysis is a fairly new concept in coverage testing. It's one most of us probably haven't seen yet, so we'll have a detailed look.

The basic idea is this: We can't eliminate all the bugs in our programs. So, WHICH bugs do we want to eliminate...?

To begin the process of risk analysis, the testing department spends some time considering the different bugs that could possibly pop up in a program. Then, we categorize these bugs on the chart illustrated below.

The horizontal axis shows how likely a bug is to occur (highest risk is on the right side of the graph).

The vertical axis shows how much damage that bug will do when it does occur (greatest damage is at the top of the graph).

Once you have a basic picture of the various types of bugs, you can concentrate on eliminating the worst ones: the bugs that are very likely to do your customer a lot of damage. In short, you'll want to work on the top right corner of the chart first.

A quick exercise: consider the infamous Pentium FDIV bug. Where on the above chart would you place that bug?

Click on the picture for the answer.