Humans play an important role in the overall reliability of engineering systems. More often accidents and systems failure are traced to human errors. Therefore, in order to have meaningful system risk analysis, the reliability of the human element must be taken into consideration. Describing the human error process by mathematical models is a key to analyzing contributing factors. Therefore, the objective of this research effort is to establish stochastic models substantiated by sound theoretic foundation to address the occurrence of human errors in the processing of the space shuttle.Elshamy, Maged and Elliott, Dawn M. (Technical Monitor)Kennedy Space CenterERROR ANALYSIS; HUMAN PERFORMANCE; STOCHASTIC PROCESSES; SYSTEMS ANALYSIS; MATHEMATICAL MODELS; RELIABILITY; SPACE SHUTTLES; FATIGUE (BIOLOGY); STRESS (PHYSIOLOGY)...