Chain-of-Events Example: Bhopal E1: Worker washes pipes without inserting slip blind E2: Water leaks into mit tank E3: Explosion occurs E4: Relief valve opens E5: MiC vented into air E6: Wind carries MIC into populated area around plant imitations of event chain models Social and organizational factors in accidents Underlying every technology is at least one basic science,,, the although the technology may be well developed long befor science emerges. Overlying every technical or civil system is a social system that provides purpose, goals, and decision criteria Ralph Miles Jr. Models need to include the social system as well as the technology and its underlying science System accidents · Software error✎✞✝✞✏✄✝✞✍✄☛✞✟☞✑③❏❑▲❼❏ ￾✂✁✄✁✄☎✆✞✝✞✟✞✠✞✡☞☛✞✆✞✝✞✌✍ c Chain−of−Events Example: Bhopal E1: Worker washes pipes without inserting slip blind E2: Water leaks into MIT tank E3: Explosion occurs E4: Relief valve opens E5: MIC vented into air E6: Wind carries MIC into populated area around plant c ✎✞✝✞✏✄✝✞✍✄☛✞✟☞✑③❏❑▲✞❽ ￾✂✁✄✁✄☎✆✞✝✞✟✞✠✞✡☞☛✞✆✞✝✞✌✍ Limitations of Event Chain Models: Social and organizational factors in accidents ❹❺✈✦q✦❵✦❡✂❨❥❜❴★✈✦✉❫❵❭♣✓❵✦❡❻❥②❧❑❵✦✐❢❬✦✈✦❤✦❨✬❤✦✉③❥⑧❴★❛❞❲❭❧❀❨★❵✦❲✦❛❜❧❀❤✦✈✦❵⑧⑨✦❲✦❛③❴★✐❞❛❢✐③❴★❵✦✈✦✐❢❵✦t ❲❜❨⑤❧❑❬✦❤✦s✦✉✦❬①❧❑❬✦❵①❧❑❵✦✐❢❬✦✈✦❤✦❨✬❤❜✉❀❥⑧♠❫❲❀❥⑩⑨✦❵①❶❷❵✦❨✬❨❢q✦❵❭♣❍❵✦❨✬❤❀❩❭❵✦q❫❨★❤✦✈✦✉❫⑨✦❵✦❸✞❤✦❡✂❵①❧❑❬✦❵ ❛❢✐❢❴✬❵✦✈✦✐❢❵❫❵✦♠❫❵✦❡✂✉✦❵✦❛❢❣①✇❞♣❍❵✦❡✂❨❥❜❴★✈✦✉❫❵❭♣❍❵✦❡✺❥②❧❑❵✦✐❢❬✦✈✦❴★✐③❲✦❨❢❤✦❡④✐❢❴⑤♣❍❴✬❨❢❛❍❥❜❛❦❧❑❵✦♠⑥❴✬❛⑦❲ ❛❢❤✦✐❢❴✬❲✦❨❢❛✓❥❦❛❜❧❑❵❜♠♥❧❑❬✦❲❭❧☞❩♦❡✂❤❭♣✓❴★q✦❵✦❛r❩❭s✦❡✺❩❭❤✦❛❢❵✦t✦✉✦❤✦❲✦❨✬❛❢t✦❲✦✈✦q❫q✦❵✦✐❢❴✬❛❢❴✬❤✦✈❫✐❢❡✂❴✪❧❑❵✦❡✂❴★❲✦❣ ❱❳❲✦❨❩❭❬❫❪❫❴★❨✬❵❜❛❞❝❢❡✂❣ Models need to include the social system as well as the technology and its underlying science. System accidents Software error