This paper introduces an analysis framework and procedure to predictively analyze human errors in performing emergency tasks, which are mostly composed of cognitive activities, in nuclear power plants. The framework focuses on the cognitive errors and provides a new perspective in the utilization of context factors into cognitive error prediction. The basic viewpoint on the occurrence of cognitive error taken in this paper is that the cognitive function failures occur from the mismatch between operator's cognitive capability and the requirements of a given task and situational condition. In accordance with this viewpoint, performance influencing factors that influence the occurrence of human errors are classified into three groups, i.e. Performance Assisting Factors (PAF), Task Characteristic Factors (TCF), and Situational Factors (SF). This classification helps analysts view the overall task context in an integrative way by considering the level of PAF with the requirements of TCF and SF to predict the possibility of cognitive function failures. Further, it enables analysts to draw specific error reduction strategies. The framework suggested was applied to the analysis of cognitive error potential for the bleed and feed operation of emergency tasks in nuclear power plants. (C) 2002 Elsevier Science Ltd. All rights reserved.