4. Conclusions and prospect
The work put forward four metrics to evaluate the safety performance of a layout. These four metrics are improper degree of facility damage risk/ human injury risk, improper degree of domino risk, accident triggered likelihood degree and evacuation convenience degree. The mathematical representations of the four metrics were also preliminary analyzed. The metrics proposed are in the preliminary discussion stage and the mathematics representations expressions need further improvement. Furthermore, to build a systematic evaluation method, more research work should be done on metric grading and comprehensive evaluation of four metrics and so on.