Page "Energy management system" Paragraph 4

Up to the early 1990s, it was common to find EMS systems being delivered based on proprietary hardware and operating systems.

Back then EMS suppliers such as Harris Controls ( now GE ), Hitachi, Cebyc, Siemens and Toshiba manufactured their own proprietary hardware.

EMS suppliers that did not manufacture their own hardware often relied on products developed by Digital Equipment, Gould Electronics and MODCOMP.

The VAX 11 / 780 from Digital Equipment was a popular choice amongst some EMS suppliers.

EMS systems such as ETAP now rely on a model based approach.

Traditional planning models and EMS models were always independently maintained and seldom in synchronism with each other.

Using EMS software like ETAP allows planners and operators to share a common model reducing the mismatch between the two and cutting model maintenance by half.

Having a common user interface also allows for easier transition of information from planning to operations.