After months of effort, a particular application was still not working, so a consultant was called in from another part of the company. He concluded that the existing approach could never be made to work reliably. While on his way home he realized how it could be done. After a few days work he had a demonstration program working and presented it to the original programming team.
    Team leader: How long does your program take when processing?
    Consultant: About 10 seconds per case.
    Team leader: But our program only takes 1 second. {Team look smug at this point}
    Consultant: But your program doesn't work. If the program doesn't have to work then I can make it as fast as you like.