The Gwinnett County school system wants to change the terms of a five-year contract it signed with the state, promising improved academic achievement in exchange for flexibility from class size requirements and other state rules.

The reason: Things have changed since 2009, when the state’s largest school system agreed to be the pilot for the education reform model developed under former Gov. Sonny Perdue and known by the acronym IE2.

Specifically, the district has added more than a dozen schools since signing the Investing in Educational Excellence contract. And the graduation test, which Gwinnett and the state agreed would be the measure of academic improvement in high schools, is being phased out and replaced with a series of end-of-course tests.

As a result, the Gwinnett school board voted late Thursday night to petition the state to be able to amend its IE2 contract to add new schools and end-of-course tests as the high school measure.

In June, the state is expected to release a report showing whether Gwinnett schools met their promised achievement goals for 2011-2012, Year 3 of their contract.

None of the county’s high schools are expected to meet their goals, Steve Flynt, Gwinnett’s associate superintendent for school leadership and operations, said recently.

He said that is largely because of the state’s decision to phase out the high school graduation test as the gateway to graduation. Fewer students are now taking the graduation test, and those who do have likely taken and failed it at least once, Flynt said.

Schools that do not meet their achievement goals for three of the five years, or at least in Year 5, have to be converted to charter schools, he said.

During the recent legislative session, lawmakers passed a law to say that the three years of improvement no longer have to be consecutive. They said that was an error in the original law.

Jennifer Falk, a parent activist, asked the school board Thursday night to take the opportunity to “discuss the merits or demerits” of IE2.

“People don’t understand it, and when they learn more about it, they have more questions than answers,” she said.

Superintendent J. Alvin Wilbanks said the reform model’s flexibility has helped the district through tough economic times.