Analytical and numerical unavailability analysis of redundant systems with dependent human error

This paper discusses a theoretical and numerical investigation of dependent human error on the failure probability of the redundant system tested periodically. Two methodologies of calculating the failure probability are developed. One is developed using the modified Karnaugh map and it can analytically compute the failure probability of the simple system. The other is developed using the minimal cut set and it gives the conservative solution. However, this method can be easily applied to the complicated system without making significant errors. (author)