Emerson

Emerson is based in Missouri. DeltaV is the distributed control system used in process plants, Ovation is the system used in power generation, and both come with a service contract and a library of control strategies written for that site.

AspenTech, which Emerson owns, sells aspenONE process-engineering and production-optimization software used by the same plant engineers. Honeywell Experion, Yokogawa Centum, ABB, Siemens, and Rockwell are the control-system alternatives, and replacing one is a plant shutdown and a revalidation.

Licensed operating companies do not swap a DCS because a rival is cheaper in year fifteen. The competition happens when a new unit is designed or when a migration off an obsolete controller is finally funded.

DeltaV and Ovation installed bases pull service, spare controllers, and engineering hours.

AspenTech models of a specific plant are not portable to a rival's flowsheet tool without rebuilding.

New unit awards are the rare moment a site will consider Honeywell, Yokogawa, or ABB.

Refinery operators run the plant from Emerson graphics and cannot improvise a different control system.

Process engineers who have built yield models in AspenTech renew that software to keep the model.