Just seven years into his teaching career, Julian Metcalfe is in charge of a programme that could transform his school.

The recently-promoted assistant head has been put in charge of the overhaul of the curriculum at Dartford grammar, as well as overseeing its computer network. Mr Metcalfe is an example of promising talent fast-tracked under Dartford’s scheme to bring on the next generation of school leaders.

TES School Leadership reported earlier this year that primary schools’

long-standing problems in finding headteachers were spreading to the secondary sector. Vacancies in January were up 50 per cent on 2000 and half of all secondary heads are due to retire in the next 10 years.

Now the impending crisis has prompted the National College for School Leadership to issue a guide to succession planning, “Shaping up to the Future”.

Its key message is that heads need to take a more imaginative approach not just to career structures but to the way they organise their schools. And they also need to make spotting and promoting talent early a school priority.

“The trick is to identify potential leaders right from their first entry into the school and start putting challenges their way,” says Russell Hobby, head of education at Hay Group. “Guide and coach their careers from that stage.

“Another tactic is to give them extra responsibility for short periods of time. Put up projects where they can display and exercise leadership without creating a formal position.”

At Dartford, Metcalfe experienced both. The school has run a series of interlocking programmes to develop staff since headteacher Tony Smith noticed the quality of candidates for middle-management posts dropping in 1992. He knew it would only be a matter of years before it would be hard to fill senior positions.

The programmes work from newly qualified teachers up. All new recruits - not just the NQTs - are given a mentor when they arrive. Schemes prepare promising new teachers for middle management, and the secondment programme takes them to the top.

Mr Metcalfe’s first promotion, to head of Year 7, came after just one year of teaching. Posts as head of Years 12 and 13 came before he was seconded to the senior leadership team last year, under the school’s programmeto give middle managers a taste of working at the top.

The secondment boosted his confidence for the big step up. “Middle management is quite a broad band and moving out of it seemed a giant step,” he says. “The secondment helped to prove it wasn’t like that.”

Programmes are open to all, take-up is good and all middle managers have a talent-spotting role, Mr Smith says. “We try to make it part of the culture of the school that we look for promise in less-experienced members of staff.”

Mr Smith says schools need to take a systematic approach to developing future school leaders, and make it a priority - a view echoed by the NCSL report.

“The best schools are almost factories of talent,” Mr Hobby says. “You can often tell them from the fact they have ex-members of staff as deputies in half the surrounding schools.”

But the report says schools should also seize the opportunity of developments such as the Children’s Act, full-service schools, curriculum reform and school federations, to take a new approach to succession planning.

“The issues surrounding leadership development and the structure of schools are tightly connected,” says Hay Group’s Russell Hobby. The role of the head is changing and the traditional staging posts of head of year or department should no longer be the only routes to the top.

Schools will need to adapt to working with other agencies such as health and social services. That is likely to require short-term projects or working groups as new ways of working are brought in - creating chances for junior staff to take a lead without creating a permanent post.

“I would also think about placing promising young leaders with other sectors for short periods of time, such as working with social care or NHS trusts,” Mr Hobby says.

The report says schools have in the past been good at setting job descriptions but less good at identifying the qualities needed for those jobs - something common in business.

Mr Hobby says schools also need to give staff good role models, to shake off the idea that good leadership means being aggressive and authoritarian.

The best leaders, he says, are usually democratic and supportive.

And support is something teachers will need as they are nurtured into their first leadership posts.

Because the biggest conundrum of leadership is that the qualities that make you a good teacher may not make youa good leader; and you may be judged not on your results but those of others.

Mr Hobby concludes: “You need a good deal of support in that first leadership role in order to enjoy it and keep moving forward.”

“Shaping up to the Future”, pound;5, available from NCSL. For an abridged version, go to: www.ncsl.org.ukresearchpublications