Confronted with a bewildering array of MBA programmes from business schools scattered all around the globe, potential students could be forgiven for being perplexed.

A full-time MBA programme is expensive, both financially and in terms of opportunity costs. Making the wrong decision has far-reaching consequences.

In an attempt at trying to establish some measure of quality control, several bodies have been formed in recent years.

AACSB International, the association for management education, which has its headquarters in St Louis, the European Foundation for Management Development in Brussels and the London-based Association of MBAs (Equis), are the most well known.

Initially, each organisation more or less operated in its home territory, but, as business schools have become increasingly international, it is now common for a school to hold two accreditations; in some instances, even three.

In April 2000, for example, Warwick Business School became the first school in the UK to secure accreditation from all three bodies, and other schools subsequently followed suit. Consequently, many more schools are now prepared to go through the laborious process of seeking accreditation.

The AACSB currently has 179 members outside the US and applications are increasing. "Business education has become really global and the schools want more of a global visibility," says Milton Blood, managing director of accreditation services at the AACSB.

Equis, the accreditation body of the Brussels-based European Foundation for Management Development, has also noted increasing demand from schools further afield: in the US, Australia, South Africa and Asia.

In its most recent clutch of accreditations, for example, Equis included, for the first time, a school in Brazil - Fundacao Getulio Vargas - and another in Australia, Curtin Business School in Perth.

Julio Urgel, dean of Spain's Instituto de Empresa and director of Equis, says that once a school becomes the first in its country to be awarded Equis accreditation, it is only a matter of time before the others follow suit.

But is accreditation really necessary? Can a school go it alone and simply rely on its brand to attract faculty and students?

While this may be the case for the top ranked schools with well-established brands, accreditation provides a very visible benchmark.

Robert Owen, director of accreditation at the Association of MBAs, says accreditation informs consumers that the programme has passed a certain threshold. Or, as Prof Urgel puts it, it offers a guarantee of quality.

"The business schools around the world are not all the same. There is a lot of diversity," says Prof Urgel. "I think the value [of accreditation] is the perception that when you are accredited [by Equis], it is a stamp that your school is truly international, that it has reached a certain standard in comparison with the reasonably well-known international schools."

Accreditation is the GMAT for business schools, he adds, and it is given more credibility on the international arena than the national equivalent.

Mr Milton concurs. "There is going to be a growing need for this kind of information [accreditation] with so many new players coming into the market and they have a great range of quality, especially with online or distance learning," he says.

Both the AACSB and Equis work with schools in helping them to prepare for accreditation. Equis provides a peer review team giving advice to schools on how they can improve, while the AACSB's candidacy programme gives schools information about what is and what is not acceptable. As a consequence, says Mr Blood, although every year some schools are rejected, fewer are now being turned down for accreditation.

So, does this mean that accreditation standards are dropping?

Mr Milton thinks not. "We have a pretty high standard in the US. Less than half of our member-schools have made the accreditation standard. It is a a pretty high hurdle." In the US, the organisation has 760 members, of which 382 are accredited.

Equis is also confident that its standards are tough enough already. "After four years of experience, we have a better idea of what is reasonable to expect from a business school," says Prof Urgel.

In the past, the AACSB, with its roots firmly in the US, has been accused of being US-centric. To counter these criticisms, it has established the blue ribbon committee to carry out a thorough review of the organisation's international accreditation standards and propose changes appropriate for global quality leadership in the next decade.

"When we began doing accreditation outside the cultures we were familiar with, we made a choice: we would not try to rewrite our standards at the outset because we did not think we were smart enough to anticipate the things we were going to experience when we went into higher education," says Mr Blood.

"We decided to learn from a set of pilot schools and then rewrite the standards. We think that we have done some learning and are trying to rewrite our standards so that they are not US-centric and to make sure that they have global applicability."

The Association of MBAs has also established an internationalisation strand. "We now have a set of criteria developed that can be applied anywhere in the world," says Mr Owen.

As for the future, with more schools entering the market, the role of accrediting bodies is likely to be accentuated rather than diminished.

Is there a chance that the various bodies will merge?

Mr Milton is in two minds. It seems likely, he says, that, at some point, the market will reject multiple accreditors and the larger accrediting bodies will merge, but he can also see a future where the organisations grow further apart, looking at different aspects of schools.

"I do not know what will happen, but I am guessing we will be going towards each other and at some point will merge. But I have no idea when," he says.

A merger of accrediting bodies would appear to be the most likely option. The Association of MBAs and the AACSB recently carried out a simultaneous accreditation at Cranfield, saving the school both time and money. It is likely that, as more schools seek accreditation and re-accreditation, they, too, will opt for this type of approach.