Purchasing is primarily responsible for inbound flows into an organization, whereas logistics spans both inbound and outbound relationships and material flows.
Purchasing was once looked upon primarily as a service function. As such, its responsibility was to meet the needs of the manufacturing function or other internal functions for which it was buying. It was not the responsibility of purchasing to question those needs, forge long-term relationships with suppliers, or to understand the needs of the end customer.
This perspective severely limited the contribution that purchasing could make to the firm. In this scenario, purchasers had to focus primarily on a narrow set of activities to serve, the needs of the internal interlaces, such as production, marketing, operations, and others who needed to procure something from outside the organization. The scope of purchasing activities was defined and limited by those inside the organization.
Purchasing focused on getting the right product or service to the right place at the right time in the right quantity, in the right condition or quality, and from the right supplier at the right price.
Typically, purchasing was not seen as an activity of strategic importance. It involved following a series of prescribed steps, which included writing up a purchase order, contacting suppliers for pricing, and sometimes following up on a supplier who failed to deliver.
The Role of Purchasing in the Supply Chain is an integration of business processes from end user through original suppliers that provide products, services, and information that add value to customers.