CHANGE VENDOR TECHNOLOGY IN A DCS MIGRATION
When cost of maintaining legacy control system and risks of plant downtime increased, desire for resolving old DCS issues and gain advantage of modern control system put the customer at two-way selection; migrate to a new DCS by staying on vendor technology or change the technology.
Today, all the main process control manufacturers have solutions for different industries, many article published to show each vendor preceded to their competitors and they are the best option for their customer in a modernization project but main process control manufacturer, Siemens, ABB, Honeywell, Yokogawa, Emerson, and Rockwell, technically all are good enough to be considered in any DCS migration project.
Modernization of control system can be done in three levels, HMI; Controller and HMI or complete change.
In upgrading HMI and controller projects staying on the vendor technology is unavoidable but, unlike vendor’s claims that keeping their technology in a migration plan have a lots of advantages and their solution not only can make plant downtime shorter but also engineering can be done easier and faster, there is not any advantage to keep vendor technology in complete system migration.
The vendors accentuate utilizing their automatic conversion tools can make engineering easier and faster but the fact is these tools are suited for HMI upgrading and not good enough for DCS logic conversion, they cannot convert 100% of logic. In a DCS migration project new logic must be rewritten by contribution of customer and information can be derivated from old logic.
Vendors claim that keeping their technology can make plant downtime shorter because they can adopt old DCS marshaling and field terminal connections by their new IO modules and this can make installation and commissioning quicker. This is true claim but not counted as an advantage in todays that many 3rd parties like phoenix contacts have wide ranges of adoption terminals, sockets and interface boards for fast migrating from legacy control systems.
The vendors endeavor to keep their customer on their technology but by realizing the fact that when migration supposed to be done during plant downtime and new logic must be rewritten manually line by line and there is not any dependency to the vendor’s products for keeping old field terminations then a customer should consider more options in migration plan just like purchasing a fresh DCS for the plant.
The best cutover migration solution for a customer is a tailor custom made solution, lots of factors should be considered for a safe, fast and effective DCS migration, choosing an independent system integrator with experience in modernization projects is the best decision that a customer can get to achieve these goals. We have successfully done many retrofit, revamp and upgrading projects in vary industries by different control systems, and the project 7304 is one of them