A supply chain is an entire system of producing and delivering a product or service, from the very beginning stage of sourcing the raw materials to the final delivery of the product or service to end-users. The supply chain lays out all aspects of the production process, including the activities involved at each stage, information that is being communicated, natural resources that are transformed into useful materials, human resources, and other components that go into the finished product or service.

Mapping out a supply chain is one of the critical steps in performing an external analysis in a strategic planning process. The importance of clearly laying out the supply chain is that it helps a company define its own market and decide where it wants to be in the future. In developing corporate-level strategies, a company often needs to make decisions on whether to operate a single line of business or enter into other related or unrelated industries.

Each stage of a supply chain is essentially a different industry, for example, raw material extraction and manufacturing. The supply chain enables a company to understand others that are involved in each of the stages, and thereby provides some insights on the attractiveness or competitiveness in industries the company might want to enter in the future.