Human Reliability Analysis in Spaceflight Applications, Part 2: Modified CREAM for Spaceflight

Human reliability analysis is a crucial for manned spaceflight success. Cognitive Reliability Error Analysis Model (CREAM) has been developed and used by the nuclear industry in predicting human error. Previously, the authors have calculated the probability error for an International Space Station ingress procedure using performance shaping factors (PSF). In this paper, the procedural risk under both ideal and common conditions using the new spaceflight specific PSFs is calculated. The risk was found to vary from the risk calculated using standard PSFs and to vary greatly depending on the spacecraft specific conditions. Under ideal conditions, the risk was found to be 1 in 88, but under common conditions, the risk was 1 in 3. Then, the new PSFs were used to analyze the impact of the three styles of training used at NASA under common conditions. Of skill-based training, task-based training, and knowledge-based training, the CREAM analysis using the new PSFs showed that skill-based training resulted in the most significant improvement in the risk of human error, from 1 in 3 to 1 in 11.