Four years ago, education officials blocked the opening of a for-profit SABIS Educational System charter school in Brockton. Will SABIS meet the same fate this month when it tries to bring its proven educational model to Lowell or expand its presence in Springfield? SABIS has earned the right to expand in Massachusetts. While the for-profit business model may offend some local sensibilities, SABIS students in Holyoke and Springfield consistently outperform peers from similar socioeconomic backgrounds.