A project to increase the number of public services available online in Northern Ireland cost more than twice what was first anticipated, the Audit Office has said.
The deal was signed in 2012, with BT contracted to provide IT solutions.
Expenditure, originally estimated at £50 million, is expected to total £110 million – more than double the original contract value – Comptroller and Auditor General Kieran Donnelly said.
He added: “It is unacceptable that the Department of Finance did not have strong controls to monitor and manage spend through the NI Direct Strategic Partner Project.
“Lessons must be learnt and departments must put strong financial management controls in place and retain sufficient expert resources throughout the duration of major contracts.”
The watchdog said it was not possible to conclude whether the major project helping to provide digital transformation had delivered value.
The BT contract funded a contact centre, developed 13 major applications, two major consultancy contracts and had cross-cutting applications across various central government departments.
Until September 2018, the Department of Finance was unable to provide details of total costs against individual projects delivered through the contract, six years after it was established.
The report welcomed a review undertaken by the department in October which explored the financial and contractual position with the project.
Robust baseline savings figures were not routinely identified at the outset of projects.
Only four of the projects delivered through the contract reported that savings have been made, yet to be verified, the Audit Office said.
Around 20 million digital transactions were completed across various new services by March this year.
The report criticised the way in which individual projects delivered through the Strategic Partner Project were prioritised, with the focus primarily on central government services rather than those most valued by the public, such as health.
The report also found that the rationale for procuring early projects was unclear – with several involving the replacement of out-of-date systems with a limited user base.
It contained 10 recommendations, including the need to make real progress in providing what citizens want, a “tell me once approach” to accessing and using digital public services.
Mr Donnelly said: “Digital transformation has the potential to significantly reduce costs and improve experiences for citizens, and this report notes that some progress has been made.
“However there is a long way to go before public services are fully citizen-focused and transformed.
“Achieving the full benefits of digital transformation must involve better collaboration and the development of truly transformational services that work across public sector organisations.”