Modern societies depend on the smooth operation of many complex systems (designed and built by humans) that provide a variety of outputs (products and services). These include transport systems (trains, buses, ferries, ships and ae- planes), communication systems (television, telephone and computer networks), utilities (water, gas and electricity networks), manufacturing plants (to produce - dustrial products and consumer durables), processing plants (to extract and process minerals and oil), hospitals (to provide services) and banks (for financial tra- actions) to name a few. Every system...