Control systems play a vital role in all aspects of modern living, from helping us drive our cars, to safely running large petrochemical complexes and power stations. According to recent industry research, instrumentation is the biggest spend item in plants. In 2010, capital expenditure for buying new instruments was estimated at $5 billion, with maintenance and operation costs projected to reach $4.9 billion. However, much of this cost is unnecessary. It arises because the technology used to plan and design instrumentation and control systems has often been developed with little regard for engineers’ and designers’ natural working methods. Procedures that can be perfectly straightforward if represented graphically—rerouting a wire, for example, or segregating cables—are all too often dependent on manual, tabular data input, which is time-consuming, expensive and prone to error.