Even as control system capabilities have advanced under the banner of commercial, off-the-shelf (COTS) computing and network technology, the task of properly configuring, integrating and maintaining these systems has become a more complex one. And at the CEPSA La Rabida refinery in Palos de la Frontera, Spain, "we were almost lost," confessed CEPSA's Francisco Arista, in a presentation to the 2012 Honeywell Users Group EMEA meeting in Istanbul.
Arista witnessed the uneasy transition at La Rabida from proprietary, purpose-built distributed control systems (DCSs) that had been relatively easy to maintain, to an automation environment filled with unfamiliar IT technology and work processes such as Microsoft operating system patches, Ethernet switches, hot fixes and anti-virus protection. Integration schemes based on OPC and Modbus communication links further complicated technology management matters.
And while the company's control systems group has begun to beef up its information technology skill set, "we are control engineers, not IT," Arista said. "There is a gap that must be covered, so we asked Honeywell to perform an assessment to see where we stood."
TPS, PKS Performance Assessed
Operations at La Rabida currently include four different clusters of Honeywell Process Solutions TPS and PKS systems of different vintages, totaling some 3,000 control loops. In order to benchmark their systems and to make sure they were operating to their full potential, CEPSA enlisted Honeywell Process Solutions to perform an Integrated Automation Assessment, beginning with the Experion PKS C300-based control system and Safety Manager installed as part of a plant expansion in 2010.
Honeywell's Integrated Automation Assessment (IAA) is a standardized process designed to evaluate the configuration state and performance of its users' Experion and TPS installations, including the FTE network, operating systems, client/server set-up, HMI graphics, security updates and anti-virus verification. The assessment also covers LCN and UCN network bandwidth and nodes capacity against recommended thresholds to assure optimal performance under all operational conditions. In addition, the final audit report provides detailed information on the tuning performance of control loops and a benchmark of users' alarm system in line with industry best practices.
"The idea was to perform an audit to compare our system against DCS best practices," said CEPSA's Pedro Villar. After two weeks of initial data collection by Honeywell, the company received after two months a final audit report complete with an executive summary of status and recommendations to improve overall performance. The six key performance aspects addressed include: control system performance, technology integration and synchronization, lifecycle planning, process control performance, alarm benchmarking and safety system performance.
Because the unit audit was of a recent vintage Experion PKS, lifecycle planning and technology integration were not yet an issue, but some server configuration problems and the need for additional server memory (RAM) were found to be impacting overall performance, Villar said. They also found that they needed to update passwords more frequently. And, compared with EEMUA best practices, some operator schematics include too much information, Villar added.
In the end, CEPSA La Rabida found the Integrated Automation Assessment process "very worthwhile" and the refinery is looking to roll it out to the rest of its operating units, Villar said. "It would have taken us a lot of time to do this work."