5. Mistakes to avoid

Do not try to use an Ishikawa cause-effect diagram in a case of interactions and logical sequences of events such as those often encountered in reliability or accident causation, for example.

The method provides a structure for reflection, but does not dispense with the need to use field investigation and creativity/brainstorming methods to identify the real causes at the root of defects. An obvious secondary cause can sometimes hide the main cause: in this case, we need to dig deeper to find the main cause.