National infrastructure provides essential services to a modern economy: energy, transport, digital communications, water supply, flood protection, and waste water / solid waste collection, treatment and disposal. The OECD estimates that globally US$53 trillion of infrastructure investment will be needed by 2030. The UK's National Infrastructure Plan set out over £460 billion of investment in the next decade, but is not yet known what effect that investment will have on the quality and reliability of national infrastructure services, the size of the economy, the resilience of society or its impacts upon the environment. Such a gap in knowledge exists because of the sheer complexity of infrastructure networks and their interactions with people and the environment. That means that there is too much guesswork, and too many untested assumptions in the planning, appraisal and design of infrastructure, from European energy networks to local drainage systems.

Our vision is for infrastructure decisions to be guided by systems analysis. When this vision is realised, decision makers will have access to, and visualisation of, information that tells them how all infrastructure systems are performing. They will have models that help to pinpoint vulnerabilities and quantify the risks of failure. They will be able to perform 'what-if' analysis of proposed investments and explore the effects of future uncertainties, such as population growth, new technologies and climate change.

The UK Infrastructure Transitions Research Consortium (ITRC) is a consortium of seven UK universities, led by the University of Oxford, which has developed unique capability in infrastructure systems analysis, modelling and decision making. Thanks to an EPSRC Programme Grant (2011-2015) the ITRC has developed and demonstrated the world's first family of national infrastructure system models (NISMOD) for analysis and long-term planning of interdependent infrastructure systems. The research is already being used by utility companies, engineering consultants, the Institution of Civil Engineers and many parts of the UK government, to analyse risks and inform billions of pounds worth of better infrastructure decisions. Infrastructure UK is now using NISMOD to analyse the National Infrastructure Plan.

The aim of MISTRAL is to develop and demonstrate a highly integrated analytics capability to inform strategic infrastructure decision making across scales, from local to global. MISTRAL will thereby radically extend infrastructure systems analysis capability:
- Downscale: from ITRC's pioneering representation of national networks to the UK's 25.7 million households and 5.2 million businesses, representing the infrastructure services they demand and the multi-scale networks through which these services are delivered.
- Upscale: from the national perspective to incorporate global interconnections via telecommunications, transport and energy networks.
- Across-scale: to other national settings outside the UK, where infrastructure needs are greatest and where systems analysis represents a huge business opportunity for UK engineering firms.
These research challenges urgently need to be tackled because infrastructure systems are interconnected across scales and prolific technological innovation is now occurring that will exploit, or may threaten, that interconnectedness. MISTRAL will push the frontiers of system research in order to quantify these opportunities and risks, providing the evidence needed to plan, invest in and design modern, sustainable and resilient infrastructure services.

Five years ago, proposing theory, methodology and network models that stretched from the household to the globe, and from the UK to different national contexts would not have been credible. Now the opportunity for multi-scale modelling is coming into sight, and ITRC, perhaps uniquely, has the capacity and ambition to take on that challenge in the MISTRAL programme.

Potential Impact:
The aim of MISTRAL is to develop and demonstrate the next generation of models, methods and tools that are needed to inform strategic infrastructure system decision making across scales from local to global. The decision makers who are responsible for strategic infrastructure planning, investment and design, work in government departments, regulators, utility companies and their consultants. This includes organisations like Infrastructure UK, Department for Transport, DECC, the Committee on Climate Change, Ofcom, the Environment Agency, RWE, BP, Shell, National Grid, Network Rail, Thames Water, SITA, CH2M, KPMG, JBA and Volterra, who are all partners in MISTRAL.

MISTRAL is intended to provide decision makers with insights that hitherto have not been available to inform crucial questions: How will infrastructure systems perform in the context of major future changes like population growth, technological change and climate change? What would be the benefits of investing in new infrastructure capacity or of endeavouring to manage demand for infrastructure services? Where are the most vulnerable points in infrastructure networks? How much is it worth investing to reduce the risk of catastrophic failure? We are answering some of these questions already, based on ITRC's first Programme Grant; for example identifying critical points in the transport network following the disruptive weather in the winter of 2013/14; and analysing the benefits of the £460billion of investments in the National Infrastructure Plan. MISTRAL will extend our analytical capability across different scales of decision making, thereby also helping to inform decision makers in devolved administrations and local authorities. With increasing devolution of decision making powers, organisations like the Greater London Authority, Transport for London, Newcastle City Council and Transport for Greater Manchester are taking increasing responsibility for infrastructure planning. We aim to have MISTRAL's infrastructure system analytics being used and informing decisions by governments, utilities and regulators at a range of scales in the UK.

MISTRAL looks upscale to understand the interdependencies between UK infrastructure systems, the EU and the world. This is of particular importance in the energy, transport, telecommunications and waste sectors. Global infrastructure networks are also of great interest to the European Investment Bank and other international investors, OECD and insurers such as Willis and Zurich Re. We will work with UK knowledge-based businesses, such as Arup and Atkins, to strengthen comparative advantage in the global infrastructure market. We aim for MISTRAL's capabilities to be used in infrastructure planning, design and analysis around the world. By working in countries like China and the UAE, where huge sums are being invested in infrastructure, we will seek to inform infrastructure decisions and demonstrate how infrastructure systems could be steered towards more sustainable outcomes. By working with the UN's infrastructure organisation, UNOPS, we intend to improve post-disaster and post-conflict infrastructure planning.

Technologies companies like Microsoft, Siemens and Improbable Worlds also want to be involved in MISTRAL because of the new datasets we will assemble, the new analytical methods we will develop and the glimpses that the research might provide of the future. We for MISTRAL's national infrastructure database to become a shared national resource, and a focal point for research and industrial collaboration.

Ultimately, consumers of infrastructure services will benefit from infrastructure systems that are more efficient, reliable, resilient and affordable. We will dedicate effort to communicating the benefits of engineering systems research, so that members of the public can engage in on an informed basis in important infrastructure decisions.