A NEW system for sorting Welsh primary and secondary schools into categories based on performance is to be unveiled by the education minister Huw Lewis this morning.

The new colour-coded system - using red, amber, yellow and green - is being billed by Welsh Government officials as an "evolution" of the old banding system, which saw secondary schools ranked in bands 1 to 5.

With the introduction of standardised tests for primary schools, they too have been brought into the categorisation system.

But the new model promises less of the "yo-yo" effect of the old system, basing a school's category on three years' worth of performance data rather than just one, and taking into account a long list of factors such as the number of pupils on free school meals, or if the school has gone through a traumatic change which may affect outcomes.

It will also use the judgement of Welsh Government-appointed mentors, known as schools challenge advisors.

For every school, two sets of measures - performance data and self-evaluation by schools - will be analysed by each of Wales' regional consortia to come up with a position in the green, yellow, amber and red spectrum.

Gwent's schools standards body, the Education Achievement Service (EAS) already colour codes its schools based on the level of help they need to improve.

The new Wales-wide model will also see schools given varying levels of intervention and help to improve based on their category.

One major change to the unpopular banding system is that now all schools could in theory be in the best category (green), without pushing others down a group.

Every three years the parameters for the categories will be reassessed, the Argus understands.

The inaugural set of statistics are due out in January for both primary and secondary schools, using data from 2012, 2013 and 2014.

Schools which are too new to have data from those years will not be included, but merged schools will be.

December bandings of one, two, three, four or five for secondary schools will be scrapped.

Dr Philip Dixon, director of the union ATL Cymru described the old banding system as "bonkers" and "crude", and said the tendency for schools to yo-yo up and down between bands was "laughable".

"The minister and his department have finally caught up with the rest of the education sector and realised that a far more intelligent accountability mechanism is needed," he said.

"The new categorisation system is more subtle and therefore more useful."

Plaid Cymru's shadow education minister Simon Thomas said scrapping banding was "a step in the right direction" but said there was still a need for improvement in measuring and raising education standards.

“This new system must identify and improve teaching standards to be successful," he said.

"I am glad that the Welsh Government has now seen sense and scrapped the system of banding."