The bungled roll-out of a new IT system across the state's public education network could have built up to 20 new schools, the NSW budget estimates committee has heard. NSW Education Minister Adrian Piccoli was forced to defend the $531 million pilot Learning Management and Business Reform (LMBR) system at Parliament House on Monday as the state opposition accused him of implementing the largest waste of taxpayer funding in the Department of Education's history. The LMBR system has been dogged by complaints and technical faults during its trial in 229 schools. Last year leaked internal emails revealed that debt collectors had been engaged to threaten schools that failed to pay suppliers of the program which was designed to manage human resources, finance, student information and payrolls. At the time the program was in disarray with under-trained, over-worked staff and principals describing it as a "complete disaster". In March the same program was responsible for thousands of TAFE students being unable to enrol because of a computer glitch. Despite the urgent need for new schools in the city and northern suburbs to cope with swelling demand, Mr Piccoli defended the half-billion dollar cost of the roll out. According to the Department of Education the average new public school should cost between $15 and $30 million. "It is not a blow out," he told the committee. "You might think that $500 million is a lot of money but it is not in the context of a very large organisation." "The original budget ($400 million under the previous Labor government) did not budget for implementation." The IT world has changed significantly since 2006, he said, adding that the NSW Department of Education, which has spent $100 billion over the past two decades, was one of the largest education department's in the southern hemisphere. "I don't know any organisation large or small who doesn't spend money on IT. You have to spend money on IT in order to have organisations run effectively." In a heated exchange with Labor committee member Walter Secord, Mr Piccoli refused to disclose what the cost of the total roll out would be, citing cabinet confidentiality. He confirmed that the total cost of the system would not exceed $1 billion. Mr Secord described the system as a "bottomless pit." "You're asking the community to approve an expenditure of between $500 and $999 million, when schools are asking to opt out the LMBR?," he said. "I'm not going to jeopardise the process of procurement by disclosing it to the market," said Mr Piccoli. "It's a cabinet decision and there are commercial in confidence reasons not to disclose it."