The endorsement of the Welsh baccalaureate by an evaluation team from Nottingham university is a turning point for education in Wales (TES Cymru, August 18). At a time when once again employers are complaining that many school-leavers do not possess those skills that the Welsh bac develops, we have everything to gain by making the roll-out of this qualification a success.

To achieve this, three challenges jump out of the evaluation report. The first is the difficulty of the advanced diploma - an experience shared by all of the pilot institutions. There is no doubt that this qualification, which is equal to an A-grade A-level, is no easy option.

Unlike A-levels, students cannot settle for a lower grade. To achieve the diploma, they have to pass every single section. However, is that a bad thing in a country whose aspiration is a world-class education system?

Our experience at St Cyres high school has proved that an 82 per cent pass rate can be achieved within an open sixth form with the right system of tutorial support, commitment from teachers and parents and, of course, funding. We have had to motivate our students to aim high and to persevere.

Not surprisingly, that ethos has also enabled them to far surpass their predecessors in their other A-level examinations.

It would be easy to make the diploma more accessible by awarding A-E grades on the same basis as A-levels. This suggestion seems to have widespread support. While there is no doubt that the assessment of the diploma needs to be revisited, I would nevertheless urge some caution and consideration of the other two challenges before adopting this superficially attractive solution.

The second challenge is of winning hearts and minds. When we launched the pilot, I remember having to sell the bac to a number of parents who had real doubts about its value. Many students shared their concerns.

Now their views are very different as they see the benefits of the education the bac provides. Would future generations work as hard as our current students if they knew they could achieve a lower grade with less effort?

It is understandable that university admissions tutors have needed to see for themselves what the qualification can give their prospective students.

They have also needed time to see how the bac fits into the bewildering array of qualifications that already exist.

Increasingly, they are recognising the benefits and more of our students are receiving offers for university places which include the bac. Employers are also consistently telling us that this is what they want.

Awarding grades for the bac could lead some students to settle for the lower grades and not strive to fulfil their potential as they have to now.

How attractive would a grade E pass in the Welsh bac be to admissions tutors, parents and employers in contrast to what our current students are achieving?

The third challenge is one of funding, and the need for a gradual roll-out of this qualification across Wales. Pilot institutions have not been able to achieve these demanding standards without putting in place skilfully managed programmes of study, and properly staffed coaching and guidance processes.

A great strength of the bac has been the timescale adopted for putting it into practice which allowed institutions and the project team to plan it properly. The decision by Jane Davidson, education, lifelong learning and skills minister, to run a longer-term pilot of this kind, and to ensure that future applications of the initiative would be based on robust external evaluation, was a laudable one in an era when governments want to see results quickly.

A gradual roll-out, with careful planning and adequate funding to staff it properly, is the only way to ensure that we put in place a qualification that will be the envy of the world.

It is wrong that a student can work towards a diploma for 18 months and then fail to achieve it, but we must not undermine the qualification’s credibility and value by adopting a solution that is superficially attractive.

There may be other solutions, such as awarding a lower-level qualification like the intermediate diploma to those who do not make the grade. There is a widespread consensus in Wales and in post-Tomlinson England that something more than our 55-year-old A-level system is required in the 21st century.

The door is now open for the Welsh bac to meet that need.

Brian Lightman is headteacher of St Cyres school, Penarth, and UK vice-president of the Association of School and College Leaders