This document provides guidance for evaluating human-system performance related to systems, equipment, and facilities in nuclear power generating stations. It summarizes specific evaluation techniques and presents rationale for their applications within the integrated systems approach to plant design, operations, and maintenance described in IEEE Std 1023. The reasons for modifying IEEE Std 845 are: *Coordinate it with IEEE Std 1023 so that they better complement each other and reduce areas of redundancy. *Make its guidance more consistent with the integrated systems approach described in IEEE Std 1023. *Improve the consideration of all related factors, such as procedures, training, human-human interactions, etc., in the evaluation of human-system performance. Revision Standard - Inactive-Reserved. " Guidance for evaluating human-system performance related to systems, equipment, andfacilities in nuclear power generating stations is provided. Specific evaluation techniques andrationale for their application within the integrated systems approach to plant design, operations,and maintenance described in IEEE Std 1023-1988 are summarized. "