How well students perform in the classroom will soon play a part in how much funding a school gets, says the Education Minister.

Speaking at the Post-Primary Teacher's Association (PPTA) annual conference in Wellington on Thursday, Hekia Parata said student achievement would "absolutely" be a factor in a review of the school funding system.

"We're very much at the beginning of this process so no decisions at all have been made as to which variables and in what way they'll be used but will student achievement and learning be one of them? Absolutely."

Parata first signalled a change to the way schools are funded back in 2013 when she described deciles as "really clumsy" and sometimes used "to explain or excuse everything".

Under the decile system, each school is allocated a number between one and 10. The higher the number the wealthier the socio-economic school community is.

Parata has previously hinted at replacing deciles with an academic progress measure but then ruled out any funding link to academic results.

Now the minister has done a u-turn and put student achievement data at the centre of any future funding model.

Parata said the current decile system "took note" of student achievement through some of its targeted funding but it wasn't a significant factor.

"You can't have a funding review of a New Zealand education system where how well kids are or aren't doing wouldn't be a part of it," she said following the conference on Thursday.

The school funding system had been "built over time by different policies" and was in need of a complete overhaul, she said.

"Obviously where we end up might be a very different place but my desire absolutely is to take count of how well our students are doing in the system and how we might support them to do better."

Previously the minister has said she wants a new funding system completed by the end of this parliamentary term.

PPTA president Angela Roberts said her biggest concern was how much the minister planned to consult the sector on the review.

Currently a cross-sector forum meets with Parata about four times a year to discuss education issues but Roberts said that wasn't a good enough platform to deal with a funding review.

"It's a lot of people that gather together, have a wee chat, there are no formal minutes, no papers to be considered, there is not the rigor required, no research evidence presented for people who go to the forum to effectively engage and kick around and develop a new work plan."

"I'm really concerned (Parata) thinks that's sufficient consultation," Roberts said.