Modeling procedure errors in switching system reliability analysis

Various elements of a reliability model which incorporates human errors in a switch are described. There are several switch states that are significant for reliability modeling of the human-machine interface in a switch, namely scheduled maintenance, hardware repair, software repair, growth, and database changes. The quality levels (QLs) of a switch which delineate the design robustness of the human-machine interface of a switch to human errors are defined. These QLs are used to modify the failure and repair rates of the switch and for quantitative analysis of switch downtime related to hardware and human errors. A repair-time model is presented, and techniques of reliability analysis pertaining to human errors are illustrated using task analysis and Markov modeling