Hundreds of schools across Northern Ireland face closure after a new report stated there were too many schools and not enough pupils.
Sir George wants Catholic and Protestant schools to co-operate more
The Bain report found that a third of schools - 440 in total - do not have a required minimum number of pupils.
Its author, Professor Sir George Bain, said this did not mean that small schools should close.
However, he warned that the current status quo could not prevail. Schools could face closure or amalgamation.
Publishing the report of the Independent Strategic Review of Education on Monday, Sir Geroge said: "There are too many schools with too few pupils." With 54,000 empty desks in schools across Northern Ireland and pupil numbers set to fall further, action had to be taken, he said.
His report recommended that the governing principle in judging the future of any school must be the quality of education it provided - but it said there should be a review of the future of small schools.
Sir George Bain examined how education is organised and funded
It also recommended that the minimum enrolment for primary schools should be 140 in urban areas and 105 in rural areas. The current minimum number advised is 60 pupils.
For post-primary schools, the minimum numbers in years eight to 12 should be 500 and for those with a sixth form there should be a minimum of 100 pupils in the sixth form. Any school with numbers below that should be examined to ensure they are able to deliver a full education for their pupils.
Sir George said schools should share more facilities and if they did so, they would get better buildings and their projects might get priority.
The report also states that the building of already approved schools could be stalled and priority given to those which agree to share facilities.
In future, Sir George, said schools should be planned to cover the needs of a geographical area rather than at present when a range of schools, Catholic, State, Integrated and Irish Language can all exist within a small area.
The report highlighted the problems created by an education system in a divided society where there are Catholic, Protestant and integrated schools at both primary and post-primary level. It advocated the promotion of sharing and collaboration between schools but made no recommendation for enforced integration.
Sir George said: "We do not advocate one single approach to integration, rather a more pervasive and inclusive strategy, focused on the dynamic process of integrating education throughout the school system.
"This should be achieved through the availability of additional resources for schools that take a more inclusive approach to `integrated education'.
"These incentives will encourage and support local schools to build on existing levels of shared facilities and staff to develop their partnership further."
The 61 recommendations are being studied by the Education minister who will announce shortly which of them she will support.