The NHS is good at recruiting high-flying graduates through the management training scheme, and despite the odd complaint in the past from those who have passed through it, it generally does a fine job (see news focus, pages 14-15). You have only to look around the service to see where its old boys and girls end up - and how quickly they get there - to realise that.

But what happens - or frequently fails to happen - next is rather more haphazard. Many an ambitious manager has at some stage in their career been frustrated at the absence of proper career development for those who have already proved their worth in the field. And, of course, the NHS is the loser when talent is not spotted and developed.

So many will join the broad welcome for health secretary Frank Dobson's talk of helping senior managers to gain the skills and experience they need - effectively grooming the best the NHS has to offer to cope with the worst it has to throw at them (see news focus, page 16). As mergers gather pace and ever larger organisations emerge, such an initiative is essential.

And yet, it must raise concerns. For any such development which appears to close down open competition for the best and most challenging jobs, or which develops into a cosy club within which a small management elite creates a successor generation in its own image, is destined to fail - and will deserve to do so. Succession planning always runs the risk of sliding into cronyism.

Indeed, that is just the charge levelled over events at one health authority in the North West (see news, pages 4-5). Secondment is a useful management tool, especially in a period of organisational uncertainty when the job to which the short-term appointment is being made may not last long. And it can be used to help good managers become better.

But it is no surprise that alarm bells have begun to ring in this case: given the traditionally high turnover rates of NHS senior managers, it stretches credulity to breaking point to describe a three-year secondment as short-term. Tom Mann may well be the best person to lead Wigan and Bolton HA. But he should be made to prove it in open competition with his peers.