Making Resilience User-Friendly: The NZTA Decision Support Tool



Case Study

Resilience is universally accepted as a desirable, even necessary, attribute for key infrastructure. However, resilience as a concept is debatable and means many things to many people, so it is important to have a clear and comprehensive understanding of its meaning, to set clear parameters and objectives in relation to a project.

The New Zealand Transport Agency commissioned researchers from Tonkin + Taylor and Ernst & Young (EY) to establish a consistent approach to transport infrastructure resilience. The second phase of the research saw the development of an updatable Decision Support Tool which would enable users to weigh up different controls in determining how best to create acceptable levels of resilience.

The provision of effective infrastructure is something that benefits all New Zealanders. The research has furthered the knowledge base and progressed dialogue around improving the resistance of infrastructure to disruptions (over the short, medium and long term). Consequently, it is of benefit to a wide audience.

Potential users include agencies and individuals making decisions about investments in the transport network across New Zealand, as well as those making investment decisions about any infrastructure asset or system. Although the Decision Support Tool is targeted at transport, it is proving able to be customised to suit any infrastructure sector.

Standardising the resilience discussion

Discussions about how to build resilience can be challenging. There is a plurality of terms, definitions and understanding of resilience and this lack of consistency makes it more difficult for decision-makers to do what is right for their communities and stakeholders.

In the first stages of the research, the team reviewed a broad range of literature in order to build a workable resilience taxonomy, or dictionary of terms. The taxonomy helps to create clarity - providing a common understanding of resilience, so that all stakeholders speak the same language - and lays the platform for better decisions to be made more consistently.

The taxonomy has three tiers:

  • A definition of resilience
  • A suite of four resilience measures
  • A glossary

The definition of resilience forms the basis for the subsequent research and the anchor for the taxonomy. Our definition of resilience is:

“Resilience is the ability of systems (including infrastructure, Government, business and communities) to proactively resist, absorb, recover from, or adapt to, disruption within a timeframe which is tolerable from a social, economic, cultural and environmental perspective”. 

Resilience measures form the next tier of the taxonomy. These measures are a short list of terms that enable users to simply and clearly categorise and communicate with a broader audience about resilience controls and the pathways to resilience. They are likely to be present in differing combinations in any resilient system.

The four measures are:

  • Robustness: The ability of systems to withstand disruption and continue to provide an acceptable level of service
  • Redundancy: Provision of functionally similar outcomes, to an acceptable standard, during lost or degraded levels of service
  • Recovery: The ability to restore an acceptable level of service after disruption
  • Leadership and governance: The ability to develop an organisational mind-set/culture of enthusiasm for responding to challenges, for example through the development of an agile and flexible asset monitoring and management programme)

Robustness includes physically strengthening assets, but can also include creating robust organisations that will be able to act even after an event has occurred. 

Redundancy means providing viable alternatives, should the worst happen. For example, if a large landslide blocks an arterial route such as the Manawatū Gorge - closing it for months or possibly permanently - are acceptable alternative routes available?

In this example, recovery actions could include prior discussions with contracting companies - who have geographically diverse access to any disruption – to ensure that service can be restored regardless of where a landslide might take place.

Leadership and governance includes the way that our leaders and institutions plan for resilience and create a culture that is able to resist, absorb and thrive in the context of change. 

The final part of the taxonomy is the glossary; a comprehensive list of terms and phrases associated with resilience, including a mix of technical, non-technical, transport specific and general terms. The glossary is included as an appendix to the full research report.

Developing the Decision Support Tool

During the research, it became obvious to the research team that there was already a constantly evolving wealth of well-researched, well-reasoned, contributions to the resilience body of literature, in particular within New Zealand.

What was missing, however, was a tool or framework that could pull all this information together. T+T and EY saw the opportunity to utilise the knowledge built up through the literature review and devise a practical, easily understood system to allow network operators and other infrastructure decision makers to consistently weigh up controls to improve resilience for communities of interest. The key design principles – flowing out of the initial research - were practicality, outcomes-focus and scalability.

The tool has six main stages that set out the steps that users should follow when considering and making decisions about resilience in relation to transport infrastructure. These are set out in this diagram.

 As well as providing a framework to explore ways of creating resilience, the tool also supports answering other questions that are key to making investment decisions about resilience, including:

  • What do we want to be resilient to?
  • How do we prioritise investment to improve resilience to disruption?
  • How should the community and other stakeholders be consulted when making decisions about resilience?
  • What is the real value of resilience – both economic and non-economic  to users and non-users?
  • What are the variables that could affect our ability to deliver resilience  for example, systemic/leadership/governance challenges?
  • Is the community prepared to pay for it?

Our approach recognises that there are other types of value in addition to traditional economic or financial value. This includes environmental, social and cultural value.  The Decision Support Tool allows consideration of the environmental, social, cultural and economic value protected or eroded as a result of each resilience decision. 

Environmental capital can be thought of as ecosystems and their constituent parts, including people and communities, and all natural and physical resources.

Social capital encompasses social cohesion and access to social networks, as well as to services and recreational facilities. 

Cultural capital is generated by the value attributed to physical natural and built environment landmarks or assets, and may be tangible or intangible.  Cultural value extends from what is valued today, to sites or artefacts which are part of New Zealand’s history.

Once the total resilience value is determined, it can be divided by the indicative financial cost of the control, to develop an indicative ‘resilience for money’ measure. Provided different controls can be broadly costed on a consistent basis, it is then possible to weigh different controls against each other (as well as potential controls on different transport systems) to understand which will provide users and decision makers with the best value for money.

Outcomes of our approach

The tool enables users to narrow down options quickly to solve a particular resilience issue - that is, it can be used to help shape thinking for the strategic or economic business case, rather than being used to make final investment decisions (i.e. at the detailed business case stage).

The implementation of the Decision Support Tool from the outset of the business case for a project allows for expanded, more creative thinking around infrastructure, as well as concepts of adding and preserving value.

Although the research was specific to transport infrastructure resilience, T+T and EY believe that, as data and best practice accumulate from use of the Decision Support Tool, it will have broader applications and could potentially be applied to the wider business case process for all infrastructure types.

Establishing the Value of Resilience NZ Transport Agency research report 614.

See the full report online here.