Heinrich's Domino model of Accidents Accident mod Injury Accident Unsafe act Fault of person Ancestry. People, not things, are the cause of accidents environment Removing any of dominoes will break sequence but said third was easiest to remove Focus on single causes Chain-of-Events Models Explain accidents in terms of multiple events, sequenced as a forward chain over time Events almost always involve component failure human error, or energy-related event Form the basis of most safety-engineering and reliability engineering analysis e.g.,Fault Tree Analysis, Probabilistic Risk Assessment, FMEA Event trees and design: e.g, redundancy, overdesign, safety margins Equipment Reduce pressure le to dama Moisture COrrosion Weakened Tank Fragments Personnel metal rupture eJected injured Use desiccant Use stainless Overdesign metal Use burst diaphragm Provide mesh Keep personnel from to keep moisture steel or coat cf thickness so to rupture before tank screen to contain viCnity cf tank while out of tank es, preventing more possible fragments. antact with failure point during and fragmentaton moisturec ✎✞✝✞✏✄✝✞✍●☛✞✟☞✑❍✒✞✒✞■❑❏❑▲✞▲ Heinrich’s Domino Model of Accidents ￾✂✁✄✁✄☎✆✞✝✞✟✞✠✞✡☞☛✞✆✞✝✞✌✍ People, not things, are the cause of accidents. but said third was easiest to remove. Removing any of dominoes will break sequence, person Unsafe act or condition Accident Injury Fault of environment Ancestry, Social Focus on single causes. Chain−of−Events Models Explain accidents in terms of multiple events, sequenced as a forward chain over time. Events almost always involve component failure, human error, or energy−related event Form the basis of most safety−engineering and reliability engineering analysis: e.g., Fault Tree Analysis, Probabilistic Risk Assessment, FMEA, Event Trees and design: e.g., redundancy, overdesign, safety margins, ... ❉✚✸✣✢✭✮✄✗❀✮✭✚✰✚✱✯✭✪❇✦✭❅ ✼✺✧✬✸✚✹❊✗✚❋✚✛✜✷ ✥✚✹✦✗✰✮ ✩✵✛✪✩✫✢✤✗✚✥✪✮✺✷ ❁✚❂ ✗❀✮✄✸✦✙ ✭ projected Equipment damaged Personnel injured Fragments ▼✯◆ metal rupture ✖✘✗✚✙✜✛✣✢✤✗✦✥✚✧★✗✪✩✫✩✤✛✚✧✬✗ ✭✩✯✮✭✚✰✚✱✲✭✚✳ ✗✪✩✵✴ Moisture Corrosion Weakened Tank Operating pressure ❙❄❚✓❯ ✹✭✚✳ ✗✜✴ ✶☞✩✤✗✦✙✚✗✪✩✵✷✢✂✢✭✚✰✮ ✶✵✩✵✗❀✩✂✮✭✷ ✰ ❂ ✗✣✩✂✩ ❖✾✤✗✚✧✬✙✚✗✣✩✤✷ ✳✚✰ ✹✦✗✪✮✭❂ ✶✵✩✵✗✦❁✜✛✚✧✩✂✮✻✙✜✷ ✭✥✚✿✜✧✭✚✳✹ ✽✻✧✬✸✣✾✤✷ ✙✚✗✦✹✦✗✣✩✤✿ ❃❄✗✜✗✚✥✦✥✚✗✜✧✩✤✸✰✚✰ ✗✚❂✺✼✺✧✬✸✚✹ ✮✄✸ ✱✗✚✗✜✥✦✹✦✸✚✷✩✂✮✺✛✜✧★✗ ✩✂✮✺✗✜✗✚❂✂✸✚✧✫✢✤✸✭✮❍✸✣✼ ✮✄✿✚✷✢✱✫✰ ✗✣✩✂✩✯✩✵✸ ✮✄✸✦✧★✛✜✥✣✮✄✛✚✧★✗✦❁✜✗✣✼✄✸✚✧★✗❀✮✭✚✰✜✱ ✩✂✢✤✧★✗✚✗✰ ✮✺✸❀✢✤✸✰✮✭✷ ✰ ✾✵✷✢✤✷ ✰ ✷✮❅❆✸✣✼✜✮✭✜✰✚✱❄❇✿✚✷ ❂ ✗ ✸✚✛✪✮✻✸✣✼✚✮✭✚✰✜✱✴ ✥✚❂ ✭✮✺✗❀✢✭✧✬❁✚✸✰ ✢✤✸✚✧★✧✬✸✣✩✤✷ ✸✰❀❇✷ ❂ ❂ ✰ ✸✣✮ ✙✚✸✜✗✣✩✤P✚✥✚✧✬✗✣✾✤✗✰✮✄✷ ✰✚✳ ✹✦✸✜✧★✗ ✥✜✸✣✩✂✩✵✷ ❁✜❂ ✗❀✼✺✧✭✚✳✹✦✗✰✮✩✵✴ ✷✮✻✷✩❆✥✜✧★✗✣✩✂✩✤✛✚✧★✷❈✤✗✚✙✜✴ ✩✂✮✺✗✜✗✚❂✺✮✺✸✦✥✜✧★✗✣✾✤✗✰✮ ✧✬✗✚✙✚✛✪✢✵✗❀✩✂✮✺✧✬✗✰✚✳✮✺✿❀✮✄✸ ✗✣◗✂✮✄✗✰✩✤✷✾✤✗✦✙ ✭✹✭✜✳ ✗ ✢✤✸✰✮✭✢✂✮ ❇✷✮✺✿ ✼✭✷ ❂ ✛✚✧✬✗✦✥✚✸✚✷ ✰✮✻✙✚✛✜✧★✷ ✰✚✳ ✭✚✰ ✙❀✼✺✧✭✚✳✹❘✗✰✮✭✮✄✷ ✸✰ ✴ ✹✦✸✚✷✩✂✮✄✛✚✧★✗✜✴ ✼✄✸✚✧✬✗✣✩✵✗✜✗✭❁✜❂ ✗✦❂ ✷✼✺✗✪✮✺✷✹✦✗✜✴