One problem with long-running IT projects is that the end result can be so far away it's difficult to know whether the goal is achievable.
No organisation knows this better than UK government, with its legacy of IT flops that never delivered on the original vision, most notably that of a single healthcare IT system under the multi-billion pound National Programme for IT.
Mark O'Neill, head of innovation and delivery in the Government Digital Service (GDS), the in-house team responsible for transforming digital services within government, said that part of the problem has been the goverment would start work on projects "without testing whether the end point was achievable or even desirable."
"Too many government IT projects have failed because they started without testing whether the end product was feasible," O'Neill told the Open Government Summit in London.
To avoid committing itself to projects that will never work, the government has turned to open source software - using it as a platform to test ideas quickly and cheaply and understand what approaches do and don't work.
Tariq Rashid, lead architect at the Home Office, said because open source software costs nothing to try out and is freely available, this makes it the perfect tool for such experimentation.
O'Neill gave the example of a project to simplify the way the public accesses a service online, where the GDS team thought that a CRM system might be the best tool for the job.
"This is a conversation asking 'Is CRM something which this organisation can understand, ramp and make use of?' An open source package allows us to have that conversation."
"This is early stage thinking. This is thinking about concepts. We have taken an open source CRM package that we are using to explore the concepts [at that early stage]," he said.
The breadth of open source software packages, said O'Neill, means that the software can be used "time and time again" to test a wide range of IT projects.
The Government Digital Service took a similar proof of concept approach when developing the alpha.gov.uk web portal - using agile development techniques to piece together open source technologies such as MongoDB, MySQL, Ruby, Scala and Nginx and hosting the site on Amazon's cloud EC2 servers, in order to rapidly develop a minimum viable product.
Elsewhere in government open source is driving down the cost of IT projects, Rashid said the Home Office had saved £400,000 on the cost of developing a website by relying on open source tools and cut £10m from the £12m cost of deploying and running a key messaging infrastructure, designed for international use, by switching to software produced by the JBoss community.
Nick Heath is chief reporter for TechRepublic UK. He writes about the technology that IT-decision makers need to know about, and the latest happenings in the European tech scene.