Emerson’s Laurie Ben and Aaron Crews presented DCS Modernization—What Does it Cost?, at the 2019 Emerson Exchange conference. Laurie opened sharing the facts that over 5800 modernization projects have been performed since the 21st century began. Emerson provides pre-Front End Engineering Design (FEED) through commissioning and startup services for these projects.
The earlier planning begins, low the costs and risks to execute a project. Front end work in the project scope and conceptual engineering phases pays dividends in the design, implementation and startup phases. Best performers can see a 50% gain in project ROI and the worst performers a 40% decrease in ROI versus average performers according to an Independent Project Analysis (IPA) study.
Early partnering with key suppliers creates additional project efficiencies to streamline work processes and take advantages on new technologies not available with the existing control system. Most of the costs of a modernization project are outside the system and include the engineering and installations costs. More modern technologies can reduce these engineering and installation costs significantly.
Rules of thumb for DCS modernization projects are $1500/point for system replacement in existing cabinets in existing rack rooms. For a complete modernization project including instrumentation and control infrastructure totally installed, commissioned and started up is $7500/point. The specifics of the installation and distances involved can affect these rule-of-thumb estimates.
Aaron discussed the impact of technology in reducing project costs. Electronic marshalling with CHARMs, although higher in cost than traditional I/O, can significantly bring down the costs in engineering and installation. Electrical & Instrumentation (E&I) engineering, installation, and cabinet space can be reduced by eliminating marshalling cabinets required in legacy control systems.
Other technical solutions include HMI replacement through DeltaV Connect applications, I/O Bus and Interface solutions for controller & I/O modernization and wiring replacement.
Aaron highlighted the tradeoffs of modernization projects from total rip & replace the legacy system with the new system to using a mix of the old and new at the I/O termination level, I/O cabinet reuse level, integrating with existing controllers and/or I/O, and more. Each path changes the costs of installation or system hardware and software required. There are also maintenance considerations as various hybrids of legacy and modern system components are in the solutions.
It’s important to spend the time in the planning process to determine the scope and path of the modernization. Make sure the costs of not only system components are factored, but also the engineering and installation costs.
