The world is no longer a business to business competition such as Company A versus Company B. Instead, Company A's supply chain competes with Company B's supply chain. A supply chain consists of nodes and flows. A node is any business entity in the supply chain such as the supplier, manufacturer, and customer. These three nodes make up the bare minimum of supply chain. If we extended that supply chain, we would see what are called intermediate nodes between the manufacturer and customer. These can be a distributor, wholesaler, and retailer. When we consider the fact that many products consist of many different subassemblies or components, it is possible to have many more nodes in an end-to-end supply chain. For example, in the automotive industry, iron ore is mined then sand blasted to become pig iron. Pig iron is forged to become steel. The steel may be shaped into coils. The coils may be cut into sheet metal. The sheet metal may be fabricated into a car body. The car body goes into final assembly of a vehicle. Finally, the vehicle is delivered to a dealership where you, the consumer, will purchase it. It is important to note that every node also has suppliers and customers. And the node itself is a supplier to its downstream customers, and simultaneously a customer to its upstream suppliers. Every supply chain for any product has the same starting point. Every supply chain also has the same ending point. Do you know what it is? The starting point and ending point are one in the same, planet earth. Everything starts with something that is mined or harvested. And ultimately, everything is disposed of. Recognizing this fact gives us an appreciation for conserving resources and the importance of sustainability efforts. There are four primary flows in a supply chain. A flow is a unidirectional or bidirectional movement of an item through the chain. We most commonly consider the downstream flow of materials. For example, manufacturer to distributor, to retailer to consumer. This is the first primary flow. Another way of looking at this is a product moves from seller to buyer. This suggests a financial implication. We need to pay for the product. The second primary flow is the upstream movement of funds, which can be via cash, check, credit card, or an electronic funds transfer. The third primary flow involves information, which goes both upstream and downstream. Information about demand flows upstream as customers place orders for a given quantity of a specific product by a requested due date. Another example of demand could be customers providing forecasts in anticipation of future requirements, predicting future orders. Information also flows downstream from suppliers to customers. Examples of downstream supply information include what products are available, packaging size, the expected lead time, and the pricing. The fourth primary flow is known as reverse logistics, which can include repairs, returns and recyclables. The reverse supply chain was once considered only as an afterthought as anything sent back upstream was handled on an as needed basis. The best companies now recognize reverse logistics upfront, and design both the forward and reverse supply chain simultaneously. Reverse logistics has become part of strategy as opposed to a reactionary tactic.