Purpose – Several arrays of literature have studied flexibility at different levels of a supply chain in order to define and conceptualise supply chain flexibility (SCF). Purchasing function is the part of a firm that has a crucial contribution in achieving flexibility on the upstream of a supply chain. The purpose of this study is to explore purchasing flexibility and its sources (how flexibility is achieved) in manufacturing companies. In this regard, the study answers two questions: 1. How is purchasing flexibility defined?, 2. How can manufacturers achieve purchasing flexibility?

Methodology – A systematic literature review was conducted and a total number of 40 academic papers were analysed to define purchasing flexibility and identify its sources in manufacturing companies. Following the systematic literature review, a case study was conducted to explore the purchasing flexibility and its sources in a manufacturing company.

Findings – The results have described the different definitions used in the literatures to address the purchasing flexibility. Results have shown that different sources of purchasing flexibility are either attributes of the suppliers network or are the result of the purchasing decisions.

Study delimitations – This study has focused on manufacturing firms. The systematic literature review was performed on English academic articles in major academic databases, which were accessible through Jönköping University network.

Contributions – The main contribution of this study is taking the systematic approach to identify sources of purchasing flexibility spread in the literature. The exploratory case study confirms that majority of sources are used by the case company to increase the purchasing flexibility. The study serves as a good tool for practitioners by gathering and compiling a list of sources for purchasing flexibility.

Keywords – Purchasing, supply chain, flexibility, upstream, manufacturing