Patient safety – Systems approach

Swiss cheese model
The systems approach to patient safety is most popularly explained via Dr James Reason’s ‘swiss cheese model’.

A systems approach recognises that in complex modern health care settings human error will always arise, but that rather than taking an individual ‘name, blame and shame’ approach, it is through emphasis on the system and its defences in place that patient safety events can be prevented from reoccurring.

The systems approach to patient safety is most popularly explained via Dr James Reason’s ‘swiss cheese model’.

The slices of cheese represent defensive patient safety strategies in place, for example some strategies may be focused on improving communication, changing the physical work environment or scheduling of staff. As systems can be imperfect, the holes in the cheese represent situations where the defences in place have not provided the intended preventative control. By layering multiple defences there is a greater likelihood that the next layer of defence will prevent a patient safety event from occurring when one hole appears. However, when multiple holes in the swiss cheese line up and none of the intended defences work, a patient safety event may occur.

The systems approach investigation of patient safety events focuses on identifying these ‘holes’ that may have contributed to the event occurring, recognising that in isolation these contributory factors may not cause harm. Once contributory factors are identified, system solutions are implemented to continue ‘plugging’ these holes within the swiss cheese. This cycle where issues are identified, analysed, solved and monitored is a core aspect of continuous quality improvement and an integral component of high-quality health care.

Watch this video on the systems approach to investigation (external site) presented by Dr Matthew Thomas.

Safety II

Safety II is an approach that accepts there will always be issues in our systems and focuses on supporting individuals and teams in working in such systems. Watch the safety II safety differently (external site) video for more information.

More information

Patient Safety Surveillance Unit

Last reviewed: 08-04-2022
Produced by

Patient Safety Surveillance Unit