There is scope for a more mature approach to setting and monitoring cost and schedule estimates by using ranges which narrow over time. The UK government has some of the most novel and complex programmes in the world. The issues that major programmes face are not unique to the public sector, with research indicating that around 75% of major programmes exceed their intended cost and schedule, including those in the private sector. Nonetheless, there are practices in the private sector that the public sector could learn from, such as there being more front-end development of a programme to define its scope, and on getting cost and schedule estimates right before committing to them. The IPA and the National Infrastructure Commission say that they are working to improve the quality of cost estimates across government, and the understanding of what a good estimate looks like. Programmes should make greater use of cost and schedule ranges to reflect the high degree of uncertainty at early stages, with the expectation that these ranges would narrow as the programme is developed further. Lessons from major projects and programmes 7 Recommendation: The IPA should encourage and support departments to use ranges for cost and schedules estimates, rather than single point numbers, and write to us setting out how it is scrutinising and improving cost and schedule estimates on major programmes.