This book looks at regulation, policy and implementation of framework agreements, supplier lists and other similar public procurement tools, with a strategic and pragmatic perspective. Whilst procurements of huge volumes and value are performed worldwide through such tools on a daily basis, and despite their complexity and diversity, this topic has rarely been studied in a systematic way. The book fills this major gap. It examines a series of public procurement systems or legal instruments selected to ensure wide coverage ¿ the UNCITRAL Model Law on Public Procurement, the World Bank, the US federal procurement system, EU law, France, Romania, and the UK pre- and post-Brexit. By deconstructing over 20 ¿clusters¿ of tools into their key features along a pattern for analysis, the book reconstructs a conceptual framework for purchasing uncertain or indefinite requirements through a transversal perspective across public procurement systems. In this way, the book provides valuable orientati