In recent years  infrastructure has been neglected.  It has become ever more urbanised and complex and more vulnerable. It might be that we are simply more aware of what is happening in a world of 24/7 news. Whatever the reason the idea of resilience has emerged as critical. The concept has resonated across developed and developing economies. It impacts a range of infrastructure sectors – often simultaneously.

Resilience is the ability of a system to withstand or recover quickly from difficult conditions. It includes the ability to prepare, absorb, recover and adapt to adverse events. Those conditions are usually some form of damage with immediate and longer term consequences that vary from slight to catastrophic. Designing, building and maintaining resilient systems to cope with foreseeable risks are a challenge. Posing an even greater challenge are those risks which are difficult or even impossible to foresee – such as those arising from low-chance but high-consequence risks and from complex interdependent processes with ‘wicked’ uncertainties, that is, problems that are difficult or impossible to solve because of incomplete, contradictory and changing requirements that are often difficult to recognise.

Resilience must imply robustness. Robustness is consequently a necessary but not sufficient condition for resilience, since the latter also includes recovery to an original state or to a state which continues to meet an acceptable level of the original purpose of the system. Sustainability logically implies resilience. A resilient system may or may not be sustainable because there are other factors, such as environmental management and consumption of resources, which are needed for sustainability. In other words, resilience is necessary but not sufficient for sustainability, but sustainability is sufficient for resilience.

Recovery after an extreme event means planning for uncertainty. A flexible suite of robust and contingent adaptation strategies is required to address a range of scenarios. This kind of planning provides us with opportunities for positive change with expanded networks, complementary aims that link reducing risks with adaptation.

Resilience checklists can help decision makers to understand the criticality of their services, the hazards, the risks, the organisations, the testing of procedures etc. However it is apparent that some overview principles are needed. Ideas that go beyond techniques and recipes to help us to think through the specific challenges that are facing us. The complexity of all that needs to be addressed is potentially overwhelming. Dealing with unforeseen high consequence events is the biggest challenge facing mankind. It is at least plausible to maintain that we are rushing headlong into more and more highly interdependent utility networks with the increasing possibility of cascading failures of a type and seriousness we have yet only glimpsed. Unless we start to think differently doing less to achieve more looks like mission impossible. Delivering resilience will require innovative systems-thinking skills of reflective practical wisdom that go beyond technique.

Four key qualities of personal resilience are integrity, innovation, practicality and getting it right first time. Learning is the key to resilience and using trauma to become better.

To provide resilience, we have to recognise that much of the available information and evidence about beliefs and values as well as all other things will be ‘wicked’. Evidence will be variously rational/irrational, intellectual/moral, subjective/objective, true/false, measured/estimated, dependable/undependable and based on evidence/intuitive judgements/guesses. Our journey to a level of resilience sufficient to cope with a changing climate requires us to steer a path through a minefield of future hazards. It requires an evolutionary observational approach that values ‘practical wisdom’ and ‘learning together’.

Delivering resilience will require innovative systems-thinking skills of practical wisdom that go beyond technique. Resilience, risk, vulnerability, robustness and sustainability need to be set not just in the dominant paradigm of scientific/technical rationality but also within a reflective practice that nurtures practical wisdom and questions ‘why’ before ‘how’.