Do you remember the amazing machine Pickering used to make breakfast in the film, Chitty Chitty Bang Bang? It whirred, clanked and cooked eggs and sausages automatically, delivering the plates on a conveyor belt. In order to make such a machine it is necessary to think through the many processes that are part of preparing a breakfast.
In 1949, before electronic computers were dreamed of, Bill Phillips, an economist at the London School of Economics produced something equivalent to the Chitty Chitty Bang Bang breakfast maker to describe the workings of the British economy.
Phillips’ machine was roughly the size of a large fridge. It was made in his landlady's garage of bits and pieces from war surplus including parts from old Lancaster bombers. It was designed to show the flow of money around the economy.
Money was represented by coloured water which was housed in a large tank at the top of the machine and called the Treasury. Water (think money) flowed from this tank into other tanks which represented health expenditure, education and various other ways in which the country could spend its money. Water could be pumped back to the header tank (the Treasury) to represent taxation. The flow of water was controlled through floats, and counterweights.
The machine was used to visually demonstrate the interaction of different parts of the economy and to simulate how the water flow needs to be in a balance. It was called MONIAC and proved an accurate model for showing how the economy worked. It was a framework which helped economic students at the time understand the complexities of money flows. Around 12 to 14 machines were built and the original prototype stands in the reception of the business school at Leeds University.
Flow diagrams are important tools in developing frameworks. When they are made into whirring and clanking machines, they are unforgettable.