Colleges rely too much on the goodwill of staff and will not become world class organisations until they are more business-like, say researchers.
Despite good results some colleges will struggle to maintain standards, let alone improve them, unless they learn from the private sector, according to a study by the Learning and Skills Development Agency.
Chris Hughes, the agency's chief executive, said: "Many are lagging behind other UK organisations in terms of their practices. This suggests that success is being built on shaky foundations and may be unsustainable.
If colleges are to close the practice and performance gap on other service providers, they must catch up with modern practices in the field of quality improvement.
"Weaknesses in service processes, together with those in staff development, suggests that relatively strong performance is being 'bought' through goodwill rather than robust systems."
These conclusions are drawn from a report on "learning excellence" by Jane Owen, Andy Robson, Dave Yarrow and Alex Appleby.
They compared a sample of 48 colleges against "world class" service organisations, a measure derived from international benchmarks looking at the way organisations are managed.
Further education was compared with a number of industries including retailing, hotels and financial services. While 46 per cent of the colleges were judged "very close" to world class, none of them had achieved the standard.
The report says colleges' efforts to increase student numbers and improve retention and pass rates come at "a high cost in financial and human terms".
Specific weaknesses among college managers included a poor understanding of the education market place, a failure to properly reward and motivate staff, an inability to achieve value for money and poor management style.
In too many cases, says the report, management decisions are based on "hunches" rather than on "sound facts, systems, practices and resources".
The researchers says these findings are supported by the comments made by staff during a separate survey earlier this year.
The research was carried out in conjunction with Northumbria University.
Barry Lovejoy, national colleges officer for Natfhe, the lecturers' union, said: "Staff clearly are the engine that drives the success of colleges.
We've always said they perform daily miracles despite frustration over low pay compared to schools.
"We hope to see an early end to the situation where this goodwill is taken for granted.
"Colleges need to make sure that rewarding their greatest asset is a financial priority."