Britain extricating itself from the European Union will be “incomparably more complex” than the first moon landing, an academic study has found.

Roland Alter, a professor at Heilbronn University in Germany who specialises in risk assessment, said he had been inspired to carry out his analysis after comments by the Brexit secretary, David Davis, that he was “running a set of projects that make the Nasa moonshot look quite simple”.

But after analysing the two situations Alter said he concluded that Davis’s analogy “missed the point”. “Both project moonshot and project Brexit are in their own way extremely complex projects. The key difference is that the USA was aware of the complexity of its undertaking.”

The paper, to be published in the journal of the German Society for Project Management early next year, analyses the comparative complexity of Britain’s withdrawal from the EU and Nasa’s first moon landing using a risk assessment model developed by the Canadian government in 2007 to determine the risk and complexity of public sector projects.

Facebook Twitter Pinterest President John F Kennedy gives a speech about travel to the moon in 1962. Photograph: UniversalImagesGroup/Getty Images

The study singles out a number of factors that make the mission launched by Theresa May’s triggering of article 50 in March 2017 more complex than the 1969 moonshot. That mission was accomplished within eight years of John F Kennedy setting the goal “of landing a man on the moon and returning him safely to the Earth”.

While the then US president had been aware of the complexity of the task from the start and deliberately fudged the timetable of the mission by adding the words “before this decade is out” in his historic speech, developments in the Brexit negotiations had revealed an “ever-widening gulf between the complexity of the project and its organisational capacity”, according to the study.

The crucial difference between the two projects, according to Alter, was that the Nasa mission had a definable “landing zone”, namely the moon. In terms of complexity, its challenges had lain mainly in developing and applying new technologies.

“The situation in Great Britain is completely different in this respect,” his paper concludes. “The project was authorised by a referendum phrased in general terms and does not have a clearly defined ‘landing zone’.”

Alter, who previously worked as a strategist for Siemens, also teaches a course on catastrophically managed projects, which includes modules on Berlin’s much-delayed new airport, the over-budget Scottish parliament at Holyrood, Airbus’s ill-fated A400M Atlas aircraft and the Iraq war. “Brexit is not part of the course yet, but it’s a hot contender for the top spot,” Alter said.