The Ministry of Defence (MoD) has pointed to software development issues as a key reason for delays in many of its major projects, a National Audit Office (NAO) report has revealed. The MoD: Major Projects report 2012, which gives a progress review of the 16 largest defence projects, shows that in the past year there has been a total forecast slippage of 139 months and increase in costs of £468m.

Accumulated, this means that since the projects had been approved, costs have risen by £6.6bn, which is about 12 per cent more than planned, and the projects have been delayed by 468 months, taking almost a third longer than originally expected. The report suggests many reasons for the surge in costs and delays but specifies software development as a key contributor and a recurring problem.

"Project delays primarily reflect a range of technical problems, such as software development, on which we have reported regularly," it said."The continuing incidence of such problems indicates the department has more to do to set realistic timescales," it added. One of the projects in which the MoD ran into problems with software development is dubbed Project Julius and involves fitting new cockpits on all of its Chinook helicopters.

"Based on the experience from Project Julius an additional six months has been added to the duration on the Chinook New Buy project to reflect the risk that flight trials could identify the need for additional software updates. Subsequent to the end of our reporting period (31 March 2012) the department has resolved the software problems more quickly than expected and the delay to Project Julius has reduced to nine months, with the first upgraded helicopters entering service in June 2012. This will be reported in full in next year's Major Projects Report," the report reads.

There were also substantial delays in the development of software for the Typhoon aircraft, and postponements relating to technical issues with the cryptographic technology in the MoD's Falcon Communications project. Amyas Morse, head of the NAO, said that the MoD must learn from previous mistakes, particularly issues that have been regularly reported.

"The MoD faces a difficult task striking a balance between delivering the capabilities it wants and those it can afford. There will always be factors over which the department has limited control, but it must do more to learn from previous projects," he 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," he concluded.