As an educational health check, it rivals NHS folklore in terms of efficiency and speed. Last week, with the publication of the controversial new banding system, secondary schools in Wales were given the diagnosis, but now they are set to spend at least nine months languishing on a waiting list for treatment.
Each of the nation's 222 comprehensives has been placed into one of five bands based on performance indicators, including attendance and GCSE results, with band 1 being the best and band 5 the worst. The system gives a mixed picture of the state of the nation's education system. There are 27 schools in band 1 and 28 in band 5. More than a quarter of Wales's 22 councils have no schools in the top band, but in more than a third there are none in the bottom band.
Education minister Leighton Andrews has promised "new" and "extensive" support to the schools in the lower bands as they embark on their "improvement journey". But as far as local authorities are concerned it is business as usual until at least September next year when their new regional school improvement services will be up and running.
Teaching unions, already concerned at the possible side-effects of a return to rankings 10 years after league tables were abolished, are furious. "Schools are to wait nine months until a new school year for any new help - that's too late and I'm worried it will be too little," said Dr Philip Dixon, director of teaching union ATL Cymru. "We have had a very swift diagnosis of the problem but, it seems, a very slow treatment."
David Evans, secretary of teaching union NUT Cymru, agreed that the delays would cause problems for schools. "What is especially concerning is that while these bandings have been announced, and the schools in the bottom bands face the stigmatisation of their rankings, we are unsure what, or even if, resources will be made available any time before September 2012 to support them," he said.
Gareth Jones, secretary of heads' union ASCL Cymru, said the wait would damage the morale of leaders whose schools were in the lower bands. "They have been publicly labelled as one of the worst-performing schools in the country and then they are frustrated in their efforts at turning things around," he said.
Earlier this month, 88 per cent of the union's members said they were doubtful or very doubtful that their local authorities could help them improve standards. Welsh medium union UCAC said that, without tailor-made support, the system would be useless.
But Chris Llewelyn, director of lifelong learning at the Welsh Local Government Association, has accused the unions of being "disingenuous".
"They should know there is a considerable amount of support going to schools already," he said. "We would expect local authorities to continue with their current arrangements until September, when the new support systems will be put in place.
"Instead of 22 local authorities there will then be four regional improvement services. They will offer bespoke arrangements that meet the needs of any given school at that time."
Mr Andrews, who was last week named Welsh politician of the year by ITV Wales, said he was expecting local authorities to provide new support for schools facing these challenges.
"I met with two of the regional consortia and they both have ambitions that none of their schools will be in band 5 in the next few years," he told BBC Radio Wales last week.
While secondary school banding caused the Welsh Government a headache, developing a primary school model has proved even more difficult.
Last week it announced that 30 per cent of primaries will be left out altogether when the system is launched next year. Schools with fewer than 10 pupils in Year 6 will not be included because the Government said that, if they were, it would not be possible to produce a "statistically robust and objective measure".
And despite concerns from Welsh inspectorate Estyn over the quality and robustness of key stage 2 teacher assessments, the Government has decided to use them as a basis for measuring performance while it develops new reading and numeracy tests.
"To wait for two years for better information will be negligent of us," Mr Andrews said.
Primary schools will know their provisional bands at Easter, before the final results are published in the summer term.