Its chief value was that it had brought calm and stability to schools and this had allowed a huge amount of work to be done on curriculum and assessment.
"The test I like to apply is the 'but for' test," he said. "Try to imagine the state we would be in but for the agreement. It's important to cast our minds back and remember how bad things were before it and therefore how absolutely crucial the agreement has been."
Mr Smith understood the requirement to demonstrate value for money. "But indicators on educational attainment, for example, are difficult to capture and improvements cannot be put down solely to the agreement," he suggested.
"We would argue that reductions in class sizes would also have benefits in terms of pupil attainment. The agreement was never designed to produce a quick return."