5 Why

The Five Why's is a simple technique to drill-down to the root cause of a problem. To use the Five Why's, start with a problem, posed as a "why" statement and keep asking "why" until you've repeated the process five times.

A example could be:

1. Why were you late to work? Because I had to get a ride to work.
2. Why did you have to hitch a ride to work? Because my car wouldn't start.
3. Why wouldn't your car start? Because the engine makes a banging noise.
4. Why does it make a noise? Because there was no oil in the engine.
5. Why no oil? Because I never checked it.

Although referred to as the "Five Why's" you can substitute other who/what/why/how words to fit the situation.

Another example:

1. Why didn't you complete your homework?  Because I didn't have time.
2. What was going on that you didn't have time?  I was busy doing other things.
3. Like what?  Jenny came over.
4. Why did Jenny come over?  Because I called her.
5. What did you say to her?  Come over and play because I'm bored and want to play.