Software development problems have been named as a key reason for forecast overspend of £468m at the Ministry of Defence over the past year, according to the National Audit Office (NAO).
The NAO report gives a progress review of the 16 largest defence projects, showing that in the past year there has been a total forecast slippage of 139 months and a £468m increase in costs.
Project delays primarily reflect a range of technical problems, such as software development, on which the NAO said it has reported regularly.
Amyas Morse, head of the National Audit Office, said: "The continuing problems highlighted in my report show that, if it is to make the most of the money available, the department has more to do to address its longstanding issues on project performance."
But the NAO said the MoD has started to make realistic trade-offs between cost, time, technical requirements and the amount of equipment to be purchased.
Some of the problems highlighted in the report include issues with developing new software for the Typhoon Future Capability programme to enable Typhoon aircraft to drop precision-guided bombs.
“The delays are due to problems with developing the software (15 months) and the consequent impact caused by the need to reschedule subsequent activities such as testing (three months). The problems have also increased the forecast cost of the project by £22m,” said the report.