The 'BBB-' rating on Advanced Technology Academy, Mich.'s revenue bonds series 2008 is based on the following credit factors: The inherent uncertainty associated with charter renewals given that the final maturity of the bonds exceeds the time horizon of the existing charter; Potential site risk given that the academy will be relocating nearly two miles from its current site, with the academy not providing school transportation to the new buildings and that it presently draws its students from three to five miles away; Operational risks with the academy operating both the existing building and new building during the 2008-2009 school year; Reliance on the academy's management company to run operations; and Low financial reserves with low liquidity, but due mostly