How to create an FDS for a revamp projectCreating an FDS is always our first aim during a plant revamp project. As the customer required us to realize all of the TDC3000 system’s functions, its system database was the focus of our investigation. The existing plant had been completed in 1995 and expanded in 2002, so some of the function definitions could be found in the TDC3000 database, but it was not possible to identify the corresponding functions in the production process. Yokogawa’s engineers checked every item in the database and worked with the customer to confirm a list of objects for the database conversion. The TDC3000 database could only show Yokogawa’s engineers what kind of function blocks had been implemented. Not enough information was available to understand the production process or the operation procedures at the polyethylene plant, both of which were of key importance in migrating to the new system. The Yokogawa personnel set about trying to interpret the database by referring to the original documents that had been released in 1995 by the licenser of the polyethylene production process and Honeywell. In addition, Yokogawa’s global engineering team assisted by providing analytical insights and tools that aided in the conversion of database control language and the visualization of logic functions. The customer’s instrumentation and operations experts were very knowledgeable about the TDC3000 system and the polyethylene plant, so Yokogawa’s engineers could clarify all unclear points in discussion with them and explain how Yokogawa would implement and realize existing functions on the Yokogawa CENTUM system, particularly those where changes were necessitated by architectural differences between the two systems.As the customer was involved throughout the FDS creation process, Yokogawa could quickly complete this work and customer approval went smoothly. The following formula expresses Yokogawa’s best practice in creating an FDS for a migration project: FDS = existing database + original documents + knowledge of customer’s expertsThree factory acceptance tests (FAT)As part of this project, Yokogawa conducted a pre-FAT, an official FAT, and a post-FAT to mitigate potential risks in the SAT phase. More than 13 experts were dispatched from the customer’s process, instrumentation, and operation departments for the official four-week FAT. Working with Yokogawa’s engineers, five teams were mobilized respectively to check all items in sequences, complex loops, complex calculations, logic, and graphics. The customer experts played a very important role by providing necessary clarifications to Yokogawa personnel on a number of points and giving many constructive suggestions on modifications.Site acceptance test (SAT)The plant was shut down for about 50 days, giving Yokogawa enough time to do a cold cut-over to the new DCS. All Honeywell terminal boards were dismantled, leaving nothing but Yokogawa system hardware.The following approach was taken to optimize the SAT process:-Digitally Enhanced (DE) protocol instruments were changed to HART or analog mode to reduce workload.-To ensure the integrity of the existing TDC3000 database, rather than immediately making changes to it to correct a problem reported by the customer, we investigated carefully to find the actual cause. For example, during the SAT, the customer requested an increase in the valve delay time to resolve a transient alarm. However, a detailed investigation found that the positions of two valve switches had been reversed.-To prevent mistakes, a policy requiring multiple approvals for function modifications requested by customer engineers was adopted.A team of over 30 people from Dushanzi, Yokogawa, and subcontractors assisted with the system installation and cut-over. Customer SatisfactionZhaoshan Sun, Chief Instrument Manager, said, “In 2007, Yokoshin Software Engineering performed flawlessly on the refinery & petrochemical complex megaproject. Their strict, careful, and effective approach in their work ensured a successful startup and stable operation of the DCS. The Dushanzi project strengthened Yokoshin’s reputation in China’s petrochemical industry. When we were considering a revamp of the legacy system at our polyethylene plant, we chose Yokoshin as our migration partner based on our assessment of their capabilities and strengths.”Mr. Sun went on to say, “Yokoshin's project manager and engineers worked closely with us to understand every technical problem and control the project schedule. The experts from Yokogawa headquarters also gave us timely support by sharing TDC3000 knowhow. To clarify details of the sequence program and calculation formulas, their engineers often worked late with us. Their rigorous, serious, and responsible approach not only helped overcome all difficult problems, but also made a good impression. The process unit has been running well and is problem-free since the start-up, and we wish to express our heartfelt thanks for this to Yokoshin!”Pre-revamp CCR with legacy Honeywell TDC3000 systemPost-revamp CCR with CENTUM systemSuccess Story Collection30PetroChina Company Limited / China



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