A national spending platform, taken on red and delivered.

OSCAR2 is the system through which public spending is reported across government. It consolidates the accounts of more than 500 public bodies and the devolved administrations: over £1 trillion of annual expenditure, and the assets and liabilities behind it. Spending reviews and the Whole of Government Accounts sit on top of it.

We took it on rated red. The business case had been approved and almost nothing else existed. No milestone plan. No programme office. No delivery mechanism. Approval had been mistaken for a start, which is a more common failure than it sounds, and a harder one to raise once a programme has been publicly signed off.

Six months to build what should have been in place from the beginning: a plan against real dependencies, the programme office, the team structure and work breakdown, commercial and supplier discipline, deliverables tracking. That infrastructure then carried the programme for the next two and a half years, which is the only test of it that matters.

We rebuilt the governance we had inherited. The project board later identified that as the single change that most improved its confidence in the programme.

Applying that rigour had a consequence nobody enjoys. Once the position was measured rather than reported, it was clear the reported one carried significant optimism, including in the benefits case. We reopened the affected components of the business case and re-agreed them with the board. Delivering against numbers you already know will not hold is not delivery; it moves the reckoning to a point where it costs more.

The team ran to 35 people: civil servants, consultants and the systems implementer. Reporting was to the Director of Public Spending.

The IBM Cognos platform went live, was adopted and was stabilised. Behind it sat consolidated finance data, a single chart of accounts and common reporting standards across more than 500 bodies, each of which had arrived with its own definitions. Multi-million-pound efficiency savings were realised in the first year.

What stayed behind was the operating model and the support function that ran the platform afterwards, staffed by the department rather than by us.