FTA와 FMECA의 통합을 통한 안전성 분석 프로세스의 개발 및 적용에 관한 연구

Abstract

Safety-critical system(SCS) which is using in various area can be taken place faults that bring loss of life, damages of property, natural disaster or environment destruction. The damage caused by faults of safety-critical software system(SCSS) related high technologies and computer is more extensive than those of SCS and it can not be easy to restore. However due to characteristics of software that is not applied by human error, we can prevent the enormous damage by improving the safety of SCSS. Therefore this paper propose software safety development process(SSDP) which is composed of system design, fault analysis, test and corrective action. And this paper also attempt to show that the safety is improved by appling SSDP to the elevator system which is SCSS. The level of system design uses function block diagram and functional fault list to see function of the elevator system. And the level of fault analysis uses FTA and FMECA to know fault causes of the elevator system. At next level which tests how SCSS safe, we can calculate risk priority number and fault ratio by using integration analysis of FMECA to FTA which is forward and backward integration, and carry out corrective action. Lastly, repeating level of test and corrective action is important until the safety is strong and fault ratio is low. So we can check that the safety is strengthened and fault ratio is minimized.