Many small charities have a very informal system of governance, but there can still be many benefits from carrying out a governance review. It makes trustees question the way they work.
Sometimes, the practices of larger charities can be appropriate for smaller ones, even if they would never normally consider them. For example, local charities might think it excessive to organise an awayday for trustees, but if they do have one they might find it helps them to think outside the box and make major improvements as a result.
It is vital that the whole board, however small, is involved in the planning process and agrees the brief before the work. Equally, it is important that the outcomes are communicated well and that any implications arising are discussed fully, then accepted formally by the board.
During such reviews, I have always found satisfaction can be gained from helping a smaller charity to envisage where it might be possible to enlarge its activities and thereby do more for its beneficiaries and those with whom it is working.
Equally, it could be that a review might lead to consideration of a different direction - or even the possibility of a merger with an organisation with similar aims.