The history behind the Common Information Model (CIM ) is one of an industry searching for solutions to problems that had long been recognized by vendors and electric utility customers alike. The efforts of many groups went into the solution, and often these groups completed one stage of the solution and another group picked up the work with little continuity. The first such group to take up the effort was the Energy Management System Architecture Task Force. This task force, under the IEEE Power Engineering Society’s Working Group 73-3, had as it purpose to think about and make recommendations on the energy management system (EMS ) architecture of the future.