By Dave Harrold
Just as employers have shifted retirement planning to the individual employee, the adoption of commercial off-the-shelf (COTS) process automation systems (PAS) has shifted more of the responsibility for their end-of-life-cycle planning from manufacturers to owner-operators.
For the past few years the aging population of instrument and automation professionals has been widely discussed at conferences and well-documented in major trade-publication. The universal question has been, What is being done to capture the knowledge of these professionals before they all retire? Likewise, ARC Advisory Group estimates that about $65 billion of installed automation systems are nearing the end of their useful lives, which means a slightly modified version of that same universal question: What is or can be done to prepare the aging installed PAS base for retirement?
Whether it is personnel- or PAS-retirement planning, the most successful outcomes are the result of early planning, heeding the advice from those who have already been there and done that, applying the wisdom of advisors and experts who understand your unique situation, regular and sufficient investments, regular plan reviews and adjustments when necessary, and trusted assistance when it comes time to executing the payout.
Retirement Planning Successes
For every horror story you may have heard about a PAS modernization project that went awry, there are hundreds of successes, mainly because these companies heeded the advice of others, sought the wisdom of experts and planned, planned, planned.
Lubrizols Deer Park, Texas, plants manufacturing process used a variety of disparate legacy PAS solutions. Desiring to improve product quality, reduce process variability and engineering and operational costs, Lubrizol created a detailed retirement plan for its PAS solutions that included incorporating Emersons DeltaV Foundation fieldbus technologies.
Bruce Johnson, Lubizols Deer Park manager of instrumentation and control says, Emersons step-wise migration solution provided us an opportunity to gain immediate benefits from our modernization efforts.
Rod Wetsch, project manager for Dakota Gasification Great Plains Synfuels in Beulah, S.D., is another beneficiary of this kind of pre-planning. We were looking for a system that could migrate without touching the field wiring, so that we could minimize downtime. Thus form factor was important to us when we were selecting a migration solution. Because we were able to capitalize on reusing the legacy systems backplanes and card cages, we only had to replace the existing electronics with Foxboros I/A Series (www.foxboro.co.uk/Products/IASeries/default.htm) form factor using the existing racks, thus completely eliminating the need to touch any field wiring. This saved us an enormous number of man hours in completing the migration, which in the end saved us money by limiting our downtime to a very narrow time frame, he says.
Erachem Comilog Incs Johnsville, Tenn., plant, with assistance from Industrial Concepts, Inc. in Hartsville, S.C., formulated a four-year PAS modernization plan to replace its existing ABB System Six with ABBs System 800xA, (www.abb.com/product/us/9AAC115756.aspx), add Profibus networks and I/O products, add seven integrated video cameras and increase the number of operator workstations, all while improving product quality, reducing operating costs and experiencing zero process downtime.
Jim Peppers of Hexcel Corp. in Decatur, Ala, explains how his company approached the decision to upgrade or replace its aging PAS.
In 2002, our management/technical team was faced with deciding if we should upgrade or replace our installed Yokogawa Centum XL system. In order to answer the question; Should we stay with Yokogawa or consider a total PAS replacement? we initiated a fairly lengthy and formalized evaluation process of major PAS manufactures. We even attended the engineering course of one of the suppliers in order to ensure that we confidently determined the best path forward for Hexcel. In the end, we determined the best solution for us was to upgrade to Yokogawas Centum CS3000 (www.yokogawa.com/dcs/products/cs/overview/dcs-cs-0101en.htm) system, says Peppers.
To ensure the evaluation remained as objective and open minded as possible, Hexcels technical/management team evaluated and ranked the top PAS contenders against the following factors (not in order of priority):
(Click here to see figure 1)
- Advanced control features
- Advanced problem solving capabilities/Predictive Maintenance/Diagnostics
- Capital expense
- Conversion on unique application code
- Migration path options
- Operator familiarity
- Plant information management system options
- Reliability/History/Track Record
- Space for expansion.
Following roughly the same strategy as Hexcel Corp., Jeff Mueller, engineering manager at National Starch and Chemical Companys Electronic Materials Division in Salisbury, N.C., was one of the key architects of National Starchs multi-year Manufacturing Control Technology Roadmap.
Challenged to improve product reproducibility, extend the life of its installed hardware base and include automation for a new, nearby manufacturing facility, Mueller and his team recognized that in order to determine the correct automation partner, they needed a detailed and formal process.
With assistance from those who use the system every day, Mueller and his team established the following nine criteria and then asked those who use and maintain the system to rank the criteria in order of importance. Heres the list (not in order of importance).
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- Batch recipe capabilities
- Installed base presence within National Starch
- Legacy control platform hardware utilization
- Open communications standard
- Operator friendliness
- Overall capability
- Program conversion/reuse
- Programmer friendliness.
Following this effort, three major PAS manufactures were invited to make presentations to address the nine focus points specifically. Following a thorough review of each suppliers offering, the team unanimously agreed that Siemens Simatic PCS 7 (https://pcs.khe.siemens.com/index.aspx?nr=1075) was the most appropriate solution supplier for their processes.
Mueller adds, We are systematically continuing to implement our modernization plan and are quite pleased with the operational improvements we have achieved with the new system. When we compare our past operational performance to what we are achieving now, we have improved our production time by 50 percent.
Though each of these projects involved different processes and different PAS solutions, each shares a common theme: Each company each invested the resources necessary to define, prioritize, evaluate, select, plan and execute a robust PAS retirement and modernization plan.
Wisdom from the Experts
During the past twenty-or-so years, every major PAS manufacturer has introduced at least one new system that resulted in making at least one old system obsolete, which means that manufacturers have been involved in hundreds, perhaps thousands, of PAS modernization projects, and they have learned a lot.
When asked about the lessons learned as a result of retirement/modernization projects, manufacturers were quite candid and indicated that with few exceptions, there is not much difference between modernizing systems from the same manufacturer verses modernizing systems from different manufacturers.
Ken Keiser, a migration specialist with Siemens Energy & Automation (www.sea.siemens.com), shared a relevant lesson about why it is important to understand user needs and expectations. Keiser explained that despite all the new features available in a recent modernization project, the operators insisted the graphics should not be changed.
The old system had numbers embedded in the graphics that corresponded to specific keyboard numbers, and the operators really liked that. Following a few meetings and prototypes, we were able to provide the operators with a look and feel they were comfortable with. What we learned is that, even though an old generation of graphics can be automatically converted to work on the new system, that,does not always mean it still makes sense. You should always include time and schedule to re-engineer converted entities, explains Keiser.
Yokogawa (www.yokogawa.com/us/) migration engineer, Lisa Faught, adds, Never underestimate the value of having the operators involved early in the project. Having the operators on board and familiar with the new graphics can go a long way toward reducing startup stress.
Following along with Keisers sage advice, during discussions with PAS manufacturers, users will be told how the manufacturer has developed entire libraries of conversion tools that they can use to save time and reduce errors. While that sounds good, savvy users will ask two very important questions: 1) Specifically, how was the conversion tool its self validated? and 2) Is the conversion tool under strict change control procedures?
Remember, control systems are programmed, often using high-level languages. This frequently equates to having ten different programmers implement the same control strategy ten different ways. If the project schedule is based on spot checks of the converted software, you will want some serious assurances that the manufacturers conversion software tools are fully capable of ensuring that the control strategy that goes into the tool is the same control strategy that comes out. Otherwise you may be debugging your control strategies at start-up.
To illustrate the point, Faught shares, I had one project where one system used structures and pointers, like C language, and the replacement system did not. The conversion tool could not handle the differences, so we had to completely restructure the batch logic and variables.
And lest you think these sorts of snafus are confined to complex control strategies, think again. Ken Keiser confided how a database conversion tool failed to take into account that early database configurations included an optional field that later became a required field. Before the software conversion tool would work, entries had to be included in each missing field. The lesson learned, says Keiser, is just because the old and new system come from the same vendor, dont assume that the databases are compatible or easily converted.
Echoing Keisers thoughts is Graham Bennett, senior migration consultant with Invensys Process Systems (http://ips.invensys.com/), who adds a few caveats of his own. Also consider the vendors ability to convert another vendors database information into the required structure. You will want assurances that they have proven automated software conversion tools and in-house experience with this specific conversion (i.e., system A to system D). Bennett suggests.
ABBs (www.abb.us/) vice president of global business development, John Murray, wasnt quite as specific but still provided sage advice. Users who choose the radical rip-and-replace strategy forego the opportunity to go back and typically incur larger upfront capital investments, experience major production downtime and acquire added costs in the areas of commissioning, training (engineers, operators and maintenance) and validation, explains Murray.
Murrays advice is right on the mark, but I would add one additional piece; discard any emotional baggage that is based on an unfounded grievance against a PAS manufacturer who says your system is now obsolete. A closer examination of the PAS modernization horror stories often revels that making hasty, emotional decisions contributed to eventual project problems.
Doing It Correctly
Each and every PAS manufacturer puts its own spin on whats required to successfully modernize an installed PAS solution, but when all the marketing talk is boiled away, the crucial steps that are required to do it correctly are
Identify and build a modernization business case, including
- Increased availability, throughput and safety
- Reduced manufacturing costs and plant emissions
- Improved product quality, response to customer requests, and ability to introduce new products.
- Conduct a detailed site assessment based on business objectives, including
- Key process measurements
- Process constraints, disturbances and limitations
- Equipment or operational limitations.
- Conduct a detailed use/requirements assessment and select a PAS modernization partner.
- Jointly develop a detailed evolution path and risk management strategy, including
Impact and resources required to replace I/O interface modules. Experienced migration specialists warn that this effort is frequently underestimated. You will be living with the I/O architecture for the next twenty or so years. Now is the time to get it right.
Interim interface cables and solutions between old and new equipment. Whenever possible, experts advise that it is best to go directly to the final solution. Even if it initially takes longer it will likely save time and reduce overall risk.
Third-party interfaces. Experts agree that much time can be saved by fully testing, in a controlled environment, all third-party interfaces, including the actual cables and connectors.
Full understanding of the state of the existing equipment, including its revision levels. All things considered, you may significantly reduce project risks by bringing all the existing (legacy) PAS devices to a common revision level before beginning any modernization efforts.
Control algorithms and tuning constants. Different PAS manufacturers use different PID (proportional, integral, derivative) algorithms that may result in undesired control actions if you plug in the old tuning constants. Understand what you have and what you are getting.
Defined terminology and agreed upon definitions. You and your PAS partners may be using the same words, but until those words have the same meaning to everyone project,t progress suffers.
Change management, or making the new PAS act like the old PAS. There will be some things that should not be changed, but you are paying for all sorts of new features and capabilities; why not take advantage of them now? If your argument against change is that you will get around to using the new features later, the reality is that you probably never will.
Footprint and layout. Newer systems generally require less space. Now may be the last time you get to rearrange cabinets, room layouts, etc. for a very long time.
Simulations. Development of simple database tiebacks from exported PAS databases and incorporating some first-principal models has become very easy. Not only can simulations help operators become familiar with the new system, but they also can also help ensure I/O points and other interfaces are functioning as expected.
Though this list represents a mere fraction of the elements users need to consider, developing a list that is relevant to your particular PAS situation does not have to be a stressful exercise, and you are not required, nor should you try to do it alone.
Stress-free retirement planning, whether for personnel or a PAS, requires a process and decision-making framework that covers an extended time horizon, draws from economics, leverages the advice and wisdom of experts who understand your unique requirements, considers a broad range of options and their influence on the outcome and is planned as though your job depends on it, because it probably does.