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Normal Accidents: Living with High-Risk Technologies. Minho Jeung Trinity Team 12/06/2005. Contents. Introduction Normal Accident Theory Three Mile Island Policy Recommendations Conclusion. 2 /11. 1. Introduction.
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Normal Accidents: Living with High-Risk Technologies Minho Jeung Trinity Team 12/06/2005
Contents • Introduction • Normal Accident Theory • Three Mile Island • Policy Recommendations • Conclusion 2/11
1. Introduction • Modern people manage to get along one wayor others meeting with an accident. • People forget accident immediately and adaptthemselves the dangerous environment • People do not have any solution to addressthe problem • Tightly coupled technology system makes people not avoid an accident • Accidents are neither abnormal nor deviatory. • Accidents are normal events for complex system. 3/11
2. Normal Accident Theory • The accidents caused by component failures • The accidents are caused by interactive complexity in the presence of tight coupled system. • Modern systems can tolerate the impact of the fault of a single component. • Normal accidents are not caused by the failure of component but the interaction of components. This picture is referenced by Introduction Accidents Analysis, Yu-Hsing Huang, CSELAB, University of Linkoping 4/11
2. Normal Accident Theory • Tightly coupled interactions: These are represented to those that do not tolerate delay. They have invariant sequences and small slack. • Loosely coupled interactions: These have the opposite characteristics. The interactions are linear or complex. The linear means simple system. The other is complex. Thus, Perrow made the following framework to classify systems according to these definitions. 5/11
3. Three Mile Island • Systemic elements led to major accidents, not the actions of the operators themselves • The combination of interactive complexity and tight coupling of the high risk systems This picture is referenced by http://www.libraries.psu.edu/tmi/images/tmi.jpg 6/11
3. Three Mile Island This picture is referenced by http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/tmi-2.gif 7/11
4. Policy Recommendations Perrow made a set of policy recommendations, which are targeted at specific systems. The three policies are: abandon, restrict, tolerate and improve. Plotted various systems on the chart, and then draws curves to split them into three categories. 8/11
5. Conclusion ► Lessons Learned • Tightly coupled system can cause catastrophic accidents. • The system is made loosed or the system has some redundancy. 9/11
5. Conclusion ► How we apply Normal Accident Theory to Studio? • The VR engine can be used in various fields of industry • It will be tightly coupled with the legacy system • Design the system to have redundancy. 10/11