Identify the problem

The first step is the most easily overlooked - define what the actual problem is. Typically a support engineer will get a call along the lines of "My program isn't working". Of course these words can be used to describe any one of three main types of error: (i) My program fails to start, (ii) my program drops dead at a given point or (iii) I disagree with the output that my program has produced.

Famous last words or software post-mortems

Under most operating systems a program will usually give the user a cyptic message just before it dies. By converting this message into a possible cause of death, you can take steps to reduce the chances of the problem happening again.