By Angela Harrison
BBC News Online education staff at the SHA conference in Harrogate
"The timings are tight," says Ken Boston
Students taking A-levels in 2008 could face fewer exams, under proposals from the exams' watchdog for England.
The Qualifications and Curriculum Authority (QCA) say cutting the number of papers - or units - in A-levels from six to four would be a vital step towards the replacement of the present exam system with a diploma.
Plans for a diploma are being worked on by the former chief inspector of schools Mike Tomlinson and his final proposals are due to go to ministers in the autumn.
The QCA would be the builder, or project manager, of any changes, said the organisation's chief executive, Ken Boston, so needed to plan ahead to manage any transition.
He sketched out a possible time-table for change to members of the Secondary Heads Association (SHA), at their annual conference in Harrogate.
The way A-levels are awarded would have to be changed before the Tomlinson reforms came in, he said, so that grades at AS-level would no longer count towards a pupil's overall grade at A-level.
He suggested teaching under the new regime could begin in September 2006, for AS awards in 2007 and A-level awards in 2008.
"This is a tight timeline, but it is not a rushed one if managed well," Ken Boston said.
"The lesson we have learned from 2002 is not to be slower, but to manage better.
"This country is behind its competitors and its education and training reforms need strategic and agile management, not expansive and relaxed contemplation."
Under the Tomlinson proposals, the whole reforms would be in place within ten years.
The diplomas would be made up of various units or subjects which would each be worth a number of points, or credits.
A student would have to reach a certain number of credits before a diploma was awarded.
The general secretary of SHA, John Dunford, welcomed Dr Boston's strategy.
"He set out a practical way forward on a reasonable time-scale in contrast to so many previous curriculum reforms which have been introduced too hastily," he said.
"When we see the Tomlinson report in full, I hope it will form part of the next election manifestos for all three main political parties so that this important educational development can be taken out of the political bear-pit."