Environmental Engineering Reference
In-Depth Information
Ecological risk
Technical-economic risk
Social risk
For environment
Fo r object
For humans
Consequences of violations
Failure, accident
Catastrophe
Past
Future
Object
(system)
Reasons for violations
Disruptions in equipment,
installations, structures
Critical external effects
Service errors
2.8 Functional model of risk of industrial systems.
• The presence of risk factors in a dose specific, dangerous (or
harmful) for the objects;
• Exposure (sensitivity) of objects to the impact factors of the danger
There is a clear similarity between failures in different industries. Failures
are usually preceded by the accumulation of defects in equipment or by
deviations from the normal course of the processes. This phase can last for
minutes, days or even years. By themselves, the defects or deviations do not
cause failure but set the stage for it. Operators usually do not notice this
phase because of inattention to the regulations or a lack of information on
the object operation, so that they do not have a sense of danger.
The next phase is an unexpected or unusual event which significantly
alters the situation. The operators try to restore the normal course of
the process, but not having full information, often only aggravate the
development of failure. Finally, in the last phase, another unexpected
event - sometimes quite small - plays the role of a shock, after which the
technical system ceases to obey the operators and there is a disaster.
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