An internal report by Glasgow University says the move to replace nine academic faculties with four colleges in one year was "over-ambitious".
Senior vice-principal Andrea Nolan also said the financial climate was not ideal, with the university seeking £20 million of cuts through voluntary redundancies which led to 264 staff leaving.
In addition, there were other significant challenges facing academics, including the development of 58 new master's degree programmes to attract overseas students.
Significant numbers of staff were also tied up developing a controversial £14m student enrolment website called MyCampus. When the site was launched much of it did not work, putting an even greater workload on staff.
Ms Nolan's report said the university had been responding to "major budgetary pressures due to the deteriorating economic climate and public funding situation".
The report summed up by saying: "The introduction of the new structure was undertaken against a backdrop of significant change, both as a result of internal commitment to delivering the strategy and as a result of funding changes in the external environment.
"With hindsight, the senior management group was overly optimistic about what it wished to achieve within the associated time-scales, given the range of other projects that were planned and those that had to be initiated as a result of changes in the external environment."
Dave Anderson, president of the Glasgow University branch of the UCU lecturers' union, said: "We have called on senior management to do more to address the concerns of staff that are overburdened as a result of restructuring and to provide the support required to ensure the university's reputation is maintained in coming years."
Under the restructuring moves unveiled in 2009, some of the university's oldest faculties were merged or renamed. The four new colleges cover Arts, Biomedicine, Engineering and Physical Sciences, and Law, Business, Social Sciences and Education.
A paper prepared for the university's court in 2009 stressed the importance of streamlining university management to ensure money was spent improving the university's performance.
The paper said a step-change was needed in areas to achieve the university's ambition to be in the world's top 50.
"Compared to those universities currently in the world's top 50 we have relatively poor international and postgraduate student numbers, our research is not published consistently in journals - and our research capability is not regarded as highly by our peers," it said.
"This paper proposes a restructuring of faculties and departments as part of the next phase of the university's actions to reach its ambitions."
A Glasgow University spokesman said: "The report on the restructure of the university is an honest assessment, not only of the considerable progress made over the past year, but also of the challenges that have arisen, and how the university aims to address these.
"Our staff have worked tremendously hard and it is because of them that our new structure is now delivering real success in areas such as new teaching and research collaborations.
"We are deeply grateful and appreciative of how staff coped in what was an incredibly challenging 12 months and many of the report's recommendations reflect their feedback and concerns.
"We are confident that the University of Glasgow is now well placed academically and financially and will continue to deliver world-class teaching and research and the best all-round experience for our students."