Modern society relies extensively on certain services and facilities for efficiency and convenience. They are so pervasive and reliable that they are taken for granted, being given the generic term "infrastructure". Infrastructure commonly requires major investment and long periods to build.

Common examples include electric power, gas, water, sewerage, roads, bridges, transport and communications. Short-term unavailability of infrastructure results in significant inconvenience, but a prologed failure can cause serious problems for people, businesses and government. In addition to an inability of users to perform many everyday functions, long-term outages could result in loss of wages for workers and profits for shareholders. This would cause severe hardship and substantially slow down the economy.

Special measures are therefore necessary to protect key components of infrastructure - "critical infrastructure" - from damage and destruction from a variety of agents. These include natural events, such as earthquakes, floods and fires as well as malicious attack from a small section of society, such as vandals, criminals and terrorists.

State Government has therefore taken the initiative to ensure that infrastructure, which may be owned or operated by either public or private organisations, is as resilient as practicable to such threats. This involves careful analysis to identify all sources of risk, to develop defences against them, and to provide for speedy remediation should any of these prove inadequate for destructive forces.