Effective process control system migration: More answers
To help those with legacy distributed control systems (DCS) that need upgrades, Control Engineering offered a March 24 webcast for professional development hour (PDH) credit, “Effective process control system migration.” Additional answers from the speakers follow, along with a link to webcast, archived for one year.
- Delaying process control system migration can risk hardware and software obsolescence and increase risk to the environment or people.
- Process control system migration requires careful and detailed planning.
- Hot-cutovers for process control systems can be achieved with detailed coordination.
Many distributed control systems (DCSs) and supervisory control and data acquisition (SCADA) systems have reached end of useful life. Are your systems past-due for an “Effective process control system migration?” Two migration experts offered advice during a March 24 webcast and additional information follows based on questions from webcast viewers attending the live broadcast. The speakers are:
- Don Bartusiak, president, Collaborative Systems Integration and co-chair of The Open Process Automation Forum.
- Lynn Njaa, business development manager, DCSNext process automation consultant, at Maverick Technologies.
More answers to process control system migration
Question: Why should migration occur, when and how?
Njaa: Why: More times than not, the reason is hardware and software obsolescence or risk to the environment or people. However, production output can justify a migration too.
When: Approval of the justification for the capital expense is when the project begins. Using a consulting firm or systems integrator can help with the justification.
How: Using a hiqhly qualified systems Integrator with a proven track record of successful migrations is your best opportunity for success.
Q: Please advise about hot cutovers, console use during cutovers, and loop checking.
Njaa: Use an experienced systems integrator/installation crew with a long history of successful hot cutovers for migration. Depending on the new control system, options for how to phase the operator interface and cutover input/output (I/O) points are planned carefully and discussed early, particularly for complex loops. One consideration is to upgrade the operator interface first, if possible. Once operations personnel are comfortable with the new look and feel of the graphics, cutover one loop at a time.
Q: Is there a different plan to capital panning for a single site migration vs. a program of work covering several sites? Are there additional front-end loading (FEL) engineering levels in this case?
Njaa: No. The FEL process is very flexible and scalable. The same phases can be executed enterprise wide or for a single site.
Q: How do you address the “cut-it-over-and-keep-everything-the-same” mentality (and budget)?
Njaa: New systems provide new capabilities, but engineering and some re-implementation work is required to take advantage of the new capabilities. This applies to control logic and schemes, alarming, schematics (ASM), field-device interfaces (Modbus vs. OPC-UA) and more.
Q: It may be too much to bite off everything at once, but how do you sell the plan (internally or externally) to get adequate funding? How do you maximize capability while minimizing regret-spend?
Njaa: Spending the time upfront with stakeholders, operations, engineering, and maintenance to address each of the items you listed and plan for them and justify the cost is how to start. The name of the game is output/profit. Bring in an experienced consulting firm or systems integrator to help with the justification. Don’t skimp on the cost of the justification and planning. This part (FEL1,2,3) of the project should cost ~6% of the total project. There is a lot of think work in the planning phase. It’s the hardest part of the project and a very important part of the project. But after it’s completely thought through, it’s just a matter of executing the task.
Q: How do you manage hot-cutovers effectively when migrating to a different human-machine interface (HMI)?
Njaa: Depending on the new control system, options for how to phase the operator interface (HMI) and cutover I/O are planned carefully and discussed early, particularly for complex loops.
Q: You mentioned that typically the DCS make and model is firmed up during FEL-2. Is there any basis for this being done in FEL-2 and not FEL-3 or any experience you would like to share?
Njaa: It’s better to do this during FEL2 because all vendors need to be solicited with a scope of work to send in budgetary proposals for. The proposals will need review for accuracy to the scope and compared for available options. FEL3 is too narrow and specific of a scope to try to do this activity. At the FEL2 capital planning level, there is far more leverage for price negotiation with potential vendors, particularly if they know they are competing.
Q: You mentioned that a high-performance HMI is 41% better in slide 14. Can you provide the reference?
Njaa: To clarify the citation, it takes 41% longer for an operator to handle an abnormal situation using a legacy DCS interface as compared to a high-performance HMI in a modern DCS. With a high-performance HMI, plant problems are recognized much earlier giving operators a chance to intervene before production is impacted. Likewise, a typical plant loses more than 5% of its total capacity every year due to disruptions caused by poor alarm response. Learn more in “The High Performance HMI Handbook” by Bill Hollifield, Dana Oliver, Ian Nimmo and Eddie Habibi, available at Amazon.
- Provide summary list of suppliers of DCS/PCS hardware/software.
- Editor’s note: Because this is an RCEP webcast, the speakers cannot mention specific vendors, however, the New Products for Engineers Database has several applicable categories and products under Control Systems.
KEYWORDS: Distributed control system migration, process control system migration
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