The authors propose a graphical method to express and analyze logical failure of human operators. Human factor is the weakest link on information security and industrial safety, and mare human mistakes have been making many severe accidents. Human thinking process is unstable and not always correct. There exist certain tendencies of cognitive misunderstanding, and people easily commit mistakes of such patterns. In the scene of computer crime, many attackers use those cognitive biases to deceive their victims. The cognitive biases are also the generator of critical misjudgments that brought severe industrial accidents.