Though SHEL and Reason models great

Though SHEL and Reason models greatly facilitate the study of human factors, but the two models have their own limitations and defects, and SHEL model of the limitations and defects in only pointed out the man-machine complex system, the human and what factors will produce cross, there may be potential hazards to human factors, but there did not indicate these aspects involving subdivision factors and factors between in what way show, contact and joint action. The model does not explicitly hidden dangers for the human factors; dose not proposes the effective method of eliminating risk and risk mitigation measures.Reason model of the limitations and defects is that it is an abstract theory, not that different level of “holes” defect is what, and how to search for accident causative factor. Secondly, this model was pointed out that there must be some hidden holes through the light, and in the practice of accident investigation, it can not correspond with all of the elements, not all incidents across all levels will meet the conditions of light, and while the partial diaphragm is only existing hidden dangers of accidents or light bypass (also is the accident in a certain elements even some elements not found on the obvious holes or have defects). Therefore, the accident is as likely to light from all elements of the loopholes in penetrable, also be from part of the elements of the area of external (or bypass), or a light through the defense shield.