The role of purchasing has changed over the past two to threedecades. The focus is no longer limited to purchasing manufacturing inputs, butalso includes sourcing of innovations from, and even co-developingtechnologies together with, suppliers. Furthermore, purchasing has obtained amuch more mature role in corporate strategy. These changes have seriousimplications for the purchasing process, its characteristics and organisation.Previous research indicates that none of the prevailing solutions, functionaldepartments and cross-functional teams, embedded in a centralised,decentralised or hybrid overall structure, deliver the expected results.Contingency theory predicts that the success of a firm depends on the fit amongcharacteristics of, amongst others, the firm’s processes and organisationalstructure. The objective of this paper is to propose and illustrate a processbasedtypological theory of purchasing and (strategic) sourcing organisation.