Safety I and Safety II

The patient safety movement started almost fifteen years ago when it was energised by the release of the Institute of Medicine report “To err is human”. Despite efforts since then to improve quality and safety many believe that little progress has been made in reducing harm caused by errors, accidents and unforeseen occurrences. There is a sense of frustration with current approaches to safety (Safety I) and disappointment that more progress has not been made. Recent developments in safety science, termed Safety II, focus on resilience, adaptive capacity and complexity science and show promise for advancing the safety agenda.


Safety I is the term given to traditional or current approaches to safety management. It includes practices such as incident reporting, investigations, root cause analysis, guidelines and targets. Most Safety I practices are reactive – they are designed to retrospectively identify what went wrong after harm has occurred. Unfortunately it is very difficult to identify the causes of incidents that occurred in the past; they are often not reported in detail, hindsight bias inevitably affects how the event is judged and there are often many competing explanations and potential actions that could be taken to prevent a recurrence. In many cases individual clinicians are viewed as responsible even though problems arise from the fact that the system has not be designed to be safe. Solutions often involve individual or team training or warnings and sanctions against individuals. Compliance with targets and procedures is also a feature of a Safety I approach. They aim to produce compliance but are based on an unrealistic view of clinical work. We know that it is not always possible to complete tasks by following a set procedure. Clinicians often have to work around problems, devising solutions and making things work for the patient despite the difficulties of the system. They need to be empowered to do this and supported to do it safely. Seen this way, targets and guidelines can constrain the very behaviours that make the system work and so can be counter-productive.


Safety II refers to a new approach which seeks to understand the ability of clinicians to adapt to problems and pressures. It is based on the view that healthcare is a complex adaptive system that is constantly changing in unexpected and unpredictable ways. The linear approach of Safety I, which involves tracing causes of events and mapping out steps in procedures, doesn’t fit this reality. In a complex adaptive system it is the humans who make things work by problem solving and adapting to the pressures in their environment. This is termed resilience as it refers to the capacity to bounce back from problems and pressures safely. Safety II is a proactive approach that seeks to strengthen clinicians’ ability to prevent problems before they occur and ensure high quality care even when there are pressures and competing demands. Learning from how things go right, rather than wrong, is an important element of Safety II and is especially powerful since things go right much more often than they go wrong. Learning how clinicians produce good care under difficult circumstances means we can ensure it happens more often.

How can we introduce SAFETY II?

It is clear that there is a place for both Safety I and Safety II approaches. Safety II does not replace Safety I but we would argue that up to now there has been too much emphasis on Safety I alone. A starting point for those interested in a Safety II approach is to consider how resilient your organisation is. Resilience is thought to involve four capacities: the ability to respond safely to problems as they occur, the ability to learn from experience and share that experience, the ability to monitor how things are going so that the need to respond can be identified as soon as possible, and the ability to anticipate future needs. How well is your organisation or team doing on these four capabilities and how can they could be strengthened? We will be producing further guidance on introducing Safety II as our work progresses. For those interested in further reading, the Health Foundation has published a thought paper on Safety I and II by Professor Erik Hollnagel. It is available from the Health Foundation website


By Janet Anderson


Our primary goals are to develop, implement and test interventions to increase organisational resilience, and to disseminate new ideas about safety throughout the NHS. Our applied work focuses on learning from successful patient outcomes and not just from failures.