Migrating an energy management system to a networked architecture

This paper chronicles the activity at Wisconsin Public Service Corporation (WPSC) that resulted in the complete migration of a traditional, late 1970s vintage, energy management system (EMS). The new environment includes networked microcomputers, minicomputers, and a corporate mainframe, and provides online access to employees outside the energy control center and some WPSC customers. In the late 1980s, WPSC was forecasting an EMS computer upgrade or replacement to address both capacity and technology needs. Reasoning that access to diverse computing resources would best position the company to accommodate the uncertain needs of the energy industry in the 1990s, WPSC chose to investigate an in-place migration to a network of computers, able to support heterogeneous hardware and operating systems. The system was developed in a modular fashion, with individual modules being deployed as soon as they were completed. The functional and technical specification was continuously enhanced as operating experience was gained from each operational module. With the migration off the original EMS computers complete, the networked system called DEMAXX (distributed energy management architecture with extensive expandability) has exceeded expectations in the areas of cost, performance, flexibility, and reliability.