This study compared evacuation effectiveness between the conventional school auditorium plan and a suggested hypothetical plan that was generated by a mathematical model, which is commonly applied in the field of industrial engineering. Recent school buildings became much more complicated in floor planning due to new social needs and modern curriculum than the old days. Nevertheless, architect's approach to floor composition in terms of fire emergency evacuation planning, still has no relation to optimized effective but relies more on an conventional school planning. Therefore, since school buildings are much more likely to be exposed to any fire related events than any other building types, emergency exit effectiveness based on spatial composition has to be seriously evaluated with a scientific method. The algorithm, which acquires the number of persons in each spatial type(node) per floor and the minimum physical distance between spatial types(arc), can propose the most optimized spatial layout per floor regarding emergency evacuation event. Consequently, this study evaluated school's fire exit effectiveness focusing on auditorium area with the scientific tool and suggested the most reliable spatial layout regarding possibile emergency evacuation event.