1.3 A PPP is a delivery model for infrastructure, characterised by long term contracts of joint working and risk sharing between the public and private sectors.
1.4 Until 2012, the primary model of PPP used in the UK was PFI. PFI was introduced in order to engage the private sector in the design, build, finance and operation of public infrastructure, with the aim of delivering good quality and well maintained assets that provide value for money for the taxpayer. It has been used across a broad range of sectors such as schools, hospitals, housing and prisons. Since its introduction, PFI has remained a small but important part of the government's overall investment in public infrastructure and services.