Mr Cleevely says that among his clients, some of the largest companies have a formal process of board assessment. But few start-ups or growing companies have got around to doing it. They need to start, many small business specialists argue. First, because the rest of the workforce see it as unfair if the directors are the only members of the company to escape being appraised.

A second reason for appraising the directors is that the board needs information on how it is doing just as much as the other employees do. Indeed, for the chief executive, appraisal of some sort is essential. Many chief executives remark on how lonely the job is and how few opportunities they get to discuss it.

Mr Cleevely says that, once smaller companies put a board appraisal process in place, they often find it easier to operate than large groups do. He says that directors of start-ups are often happier to receive criticism than their counterparts in large organisations because smaller companies are less hierarchical. "There's already a more democratic ethos in some younger companies. They have to be meritocratic to survive."

So how should companies assess their boards? "It is the chairman's job to ensure the regular, at least annual, appraisal of each director," says Bob Garratt, a writer and consultant on boards. "At its crudest, this can involve having the board together in one room, and having a sheet of paper for each director." Each director can then write down what they have achieved, how they can improve and how the board as a whole is functioning.

Mr Garratt adds: "At the other end of the assessment scale is the 360 degree appraisal. Here each director is appraised in a systematic manner by a combination of his or her boss, the chairman, their fellow directors, and any direct reports they may have. This is a very powerful process. It helps greatly in stopping directors, especially executive directors, trying to micro-manage the business from the boardroom instead of getting on with the job of directing."

Bernard Taylor, director of the Centre for Board Effectiveness at Henley Management College, says that even in the largest companies, there are many methods for assessing the board. "You have a number of companies that have a self-assessment process. The chairman will orchestrate it. He will meet each director individually to ask how it's going in a fairly informal way. You don't want to discuss that in an open session. It's a very sensitive subject," he says. The whole board might also meet to discuss its progress. "You might have an outsider who comes in and distributes questionnaires to each director to form the basis of the meeting. You would ask: what do we think are the board's key tasks and how are each of the committees working?"

Mr Dunne believes the chairman should assess the chief executive. The chief executive should appraise the executive directors. The chairman and chief executive should assess the non-executive directors. Who should appraise the chairman? "That's quite a tough one," Mr Dunne says. "In a venture capital-backed business it's quite straightforward"it's the venture capitalists and the chief executive. In a lot of public companies, the non-executives will do it."