Figure 1.3 takes a basic view of the network, with a focal firm linked to three upstream suppliers and three downstream customers. If we then add material flow and information flow to this basic model, and place a boundary around the net-work, Figure 1.4 shows the network in context. Here we have added arrows showing the logistics contribution of material and information flows, together with the time dimension. Material flows from primary manufacture (for example farming, mining or forestry) through various stages of the network to the end-customer. Material flow represents the supply of product through the network in response to demand from the next (succeeding) organisation. Information flow broadcasts demand from the end-customer to preceding organisations in the network. The time dimension addresses the question ‘How long does it take to get from primary source to the end-customer?’ That is, how long does it take to get product through the various stages from one end of the supply chain to the other? Time is import-ant because it measures how quickly a given network can respond to demand from the end-customer. In fact, the concept of flow is based on time: