Public procurement contracts represent a major share of any country’s GDP and public expenditure budget. This fact alone provides sound reasons for analysing the performance of public procurement operations at all levels. Performance measurement is about seeking to answer the fundamental question of whether the procurement system and operations ultimately deliver in accordance with the main objectives set. SIGMA Brief 21 explains the rationale for measuring performance in public procurement, the benefits of effective performance management and also gives guidance on how to measure performance. Finally, it sets out some examples of methodologies which could be used to determine performance at different levels of the public procurement system.