Senior responsible owners move, delivery partners rotate faster, and the reasoning behind a programme is rarely written down in a form that survives either. The document lasts. Why an option was discounted, who agreed it, and what was overruled does not.
It shows up later as an inability to evidence anything. In April 2025 the Evaluation Task Force reported that two-thirds of the then Government Major Projects Portfolio, representing £456bn of whole-life cost, had no good-quality evaluation plan — with the weakest coverage in government transformation and ICT. The portfolio has since been reorganised and is smaller, so treat that as the last published portfolio-wide measure rather than a current one.
The same thing recurs across the published record: appraisal done to clear an approval rather than to choose between options, benefits defined once and never tracked, and risk registers maintained for assurance rather than for managing anything.
Source: Evaluation Task Force, evaluation of the Government Major Projects Portfolio, April 2025