Process Hazard Analysis(PHA) have been performed for a risk management of process (petrochemical) industry for nearly 50 years. There are many PHA methods for application in the process industry, Hazop Study method has been recognized as a good method used typically in most of phase of process plant. And also there was inconvenient opinion that Hazop Study is too resource (man power, time etc.) consuming comparing its result performance (a quality of recommendations) for a good operating and existing plant. In this study, two types of PHA method - checklist and K-PSR - were performed respectively for a new para-xylene(PX)plant and 30 year old PX plant. Past history and experience of incident, operation, maintenance and so on are very important in PHA by those two methods. The higher effectiveness were realized in PHA by a checklist and K-PSR Method than prior Hazop study. And also some suggestions including PHA cycle determination, RBPS application, Follow-up plan of PHA result etc. were proposed about PHA improvement measures for a best risk management.

Abstract
 1. 서 론
 2. 위험성 재평가 준비
  2.1 평가 대상 공정
  2.2 평가 기법 선정
  2.3 평가 자료 준비 및 평가팀 구성
 3. Checklist 위험성 재평가
  3.1 Checklist 평가 항목 개요
  3.2 Checklist 평가 내용 및 결과
  3.3 Checklist 평가 효과
 4. K-PSR 위험성 재평가
  4.1 K-PSR 평가 항목 개요
  4.2 K-PSR 평가 내용 및 결과
  4.3 K-PSR 평가 효과
 5. 위험성 평가 개선 방안 검토
  5.1 위험성평가 수행 주기 변경
  5.2 위험성평가 기법 순환 적용
  5.3 정성적 평가와 정량적 평가의 연계 수행
  5.4 위험도기반 공정안전관리 적용
  5.5 위험성평가 사후 관리
 6. 결론
 7. References

• 임종우(인천대학교 안전공학과) | Jong Woo Lim
• 우인성(인천대학교 안전공학과) | In Sung Woo Corresponding Author