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Analysing system failure

Multiple-cause and sign diagrams can highlight system failure. The step introduces an exercise to identify points of failure and possible mitigation.


Analysing failure with multiple cause diagrams

Imagine that as the manager of a hospital you have the problem that patients are spending an unacceptable time on trolleys in a corridor next to the admissions unit, sometimes hours or even days. The following have been identified as relevant factors:

  • patients waiting in corridor
  • too many people being admitted
  • too many people are presenting at A&E
  • too many accidents and incidents
  • no beds are available in the wards
  • there are insufficient beds for the population
  • beds are blocked by elderly patients
  • some patients have no carer at their home
  • transport provision is unreliable and patients cannot be discharged
  • there is no accommodation available in residential homes

(a) Arrange these factors into a multiple cause diagram

(b) Put pluses and minuses on your arrows to make a sign graph

You may have to adjust your multiple cause diagram to make it into a sign diagram. This reflects the usual evolutionary nature of systems thinking. The diagramming tools in these exercises often help and inform the process of reflection on a system and its behaviour.

You can share your drawings and receive comments on them on a Padlet wall here. Click the back button to return here.

When you have finished move on to the next step to see our diagrams.

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Systems Thinking and Complexity

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