Week 8 P2 Flashcards
The systemic model considers the system as a whole and..
Interactions between components
The systemic approach acknowledges accidents have a complex cause and can’t be similarly predicted. T/F?
True
How does Perrow define a system accident ?
As a failure in the subsystem or whole system that damages >1 unit and disrupts the ongoing/future output of the system
What is the definition of disruption ?
Where the system output ceases or falls to an extent that immediate repairs are required
Tightly coupled systems have ___ dependencies between parts.
High
Complex systems with hazardous and numerous technologies, (ie nuclear power, aircraft, petrochemical plants etc) see much less control over high dependencies and interactions between system parts. These systems are…
Highly coupled
Have complex and nonlinear interactions
Have unfamiliar, unplanned and unexpected manifestations
For accidents in complex systems, these are often not discernible or comprehensible compared to linear interactions with familiar/expected accidents. How are accidents prevented ?
Through identifying and correcting dysfunctional interactions
The systemic accident model approach is an extension of Perrow’s concept. How is it different ?
It considers the whole system performance not just dysfunctional interactions
How are complex systems characterised ?
By existing dynamic couplings and interactions between system components which are kept in dynamic equilibrium by feedback loops of information and control
How is performance variability assessed? Is it considered the main explanation for accidents?
Considering each coupling’s variation
In the systemic model it is considered the main explanation of accidents
In the systemic model it is assumed that natural variability can lead to the degradation of…
The system performance or lead to an accident.
(Definition of a normal accident)
How are systematic accidents prevented ?
By determining the system performance variability, the variability of each interaction, and managing and controlling this. This is very hard to achieve for complex systems
It is assumed that tightly coupled and highly interactive systems have high accident rates. Is this always true?
Not for aircraft where the accident rate is very low
Many loosely coupled and less interactive systems like mining and manufacturing plants have higher accident rates
What is the problem with high end systemic recommendations?
They are resource demanding and not easily applicable compared to simpler recommendations
Appropriate decision making mechanisms are required to make priorities based on
The positive effect of measures compared to others
