A global supply chain involves various departments within a firm and external partners to manage the end-to-end processes relating to selling the firm's products, including sourcing, distribution, transportation, warehousing, sales, and customer service. The technology used to connect people and processes is critical to operating a successful supply chain. Supply chains are complex and therefore subject to problems. Those managing the operations need to have sound strategies in place and re-assess those strategies regularly to ensure that the supply chain performs effectively.