Sub-questions

Have programme cost and duration estimates been developed through use of systematic and appropriate methods?

Have the estimates been validated?

Do the cost estimates cover all elements of the programme?

Is it clear where costs have been excluded?

Do costings make allowance for risk?

Do the scheduling estimates cover all elements of the programme?

Does the schedule reflect dependencies on activities managed within the programme and those external to it?

Does the programme schedule have the majority of its tasks on the critical path or is there some flexibility in the scheduling of individual tasks?

Does the programme have identified contingency sums aligned with its risks and uncertainties that adequately reflect the level of complexity?

Does the programme record and continually update its critical path?

Are realistic milestone dates consistently reported to leadership and the organisation?

Essential evidence

Breakdown of programme cost into main components - (cost categories/contract packages, programme management overhead) including allowance for risk.

Planned start and end dates of programme phases and changes to these schedules during the programme.

Cost and schedule - examples from our studies

Our 2018 Investigation into land and property acquisition for Phase One (London - West Midlands) of the High Speed 2 programme found that the estimated cost for HS2 Ltd to buy the required land and property was very immature at the start of the programme in 2009. In 2012, HS2 Ltd estimated that the acquisition programme would cost £1,120 million (2011 prices), by 2013 the estimate was £1,608 million (2011 prices), and by 2017 it was £3,295 million (2015 prices). Costs increased due to inflation, but also through changes to the route and a more detailed understanding about the land required. Additional discretionary compensation schemes were also introduced by government. Despite these changes, HS2 Ltd believed costs would remain within the available funding, although significant uncertainty remained about the final cost.

Our 2016 report found that the schedule for the infrastructure programme for Modernising the Great Western railway was unrealistic, resulting in significant subsequent cost increases. The electrification schedule was not based on a bottom-up understanding of what the works would involve and in 2014 Network Rail still underestimated the numbers of bridges to be modified, the complexity of planning permission and other consents, and was too optimistic about the productivity of new technology. As a result, the estimated cost of electrification between Maidenhead and Cardiff increased by £1.2 billion (70%) between 2014 and 2015 even though Network Rail believed it could reliably estimate the cost in 2014. Since 2015, Network Rail had taken steps to improve its programme management, including cost estimation, monitoring and governance, and strengthened its collaboration with contractors and the wider rail construction industry.

Other relevant reports

Progress delivering the 'One Mission, One Bank' strategy (paragraph 7)

The Sheffield to Rotherham tram-train project: investigation into the modification of the national rail network (paragraphs 4 and 8)

The new generation electronic monitoring programme (paragraph 8)

The Equipment Plan 2018 to 2028 (paragraphs 6 and 7)

Early progress in transforming courts and tribunals (paragraphs 9, 10 and 12)

The Nuclear Decommissioning Authority: progress with reducing risk at Sellafield (paragraphs 9, 10 and 12)