A best practice approach for infrastructure projects and programmes Central to project discipline is the use of expert, evidence-based cost estimates. Establishing an early and accurate cost estimate is a key factor in selecting the right projects and delivering them on time and on budget. However, a cost estimate is not a single figure that is determined at the start of a project and fixed from therein. The cost estimate evolves over time as the project matures and is inherently linked to the development of the project scope and schedule. The cost estimate should be presented as a range to account for the level of risk and uncertainty inherent in the project and this range should decrease as the project develops. At the heart of developing a robust cost estimate of the three ‘P’s: - Principles - of cost estimating to get the basics right and address common pitfalls - People - roles, skills and behaviours needed to deliver, assure and own the cost estimate - Performance - steps for improving the quality and consistency of cost estimates and surrounding processes This document sets out, for the first time, a best practice approach to cost estimating which should be used by all major infrastructure projects and programmes in the UK. This guidance document is for all project delivery team members including Senior Responsible Owners and Project Directors. Nothing less than world class delivery will do and this document is another step towards that vision, helping those involved in project delivery to thrive and deliver projects and programmes to the benefit of all the citizens in the United Kingdom. Nick Smallwood Chief Executive, Infrastructure and Projects Authority Source: https://assets.publishing.service.gov.uk/media/6050c9528fa8f55d324b0c84/IPA_Cost_Estimating_Guidance.pdf