Asset management technologies offer the potential to help companies in the process industries stem the high cost of maintenance by ensuring production equipment is maintained for maximum performance at minimum cost. But, can asset management software save money in an already efficiently run plant? How can asset management software help achieve savings, and how much can be saved? Based o...
Asset management technologies offer the potential to help companies in the process industries stem the high cost of maintenance by ensuring production equipment is maintained for maximum performance at minimum cost.
But, can asset management software save money in an already efficiently run plant? How can asset management software help achieve savings, and how much can be saved?
Based on typical maintenance activities and time periods, a Microsoft Excel based calculator provides potential savings using smart instrumentation and asset management software (See Free AMS calculator sidebar).
Finding the savings
According to a 1996 report issued by E.I. DuPont de Nemours Co. (Wilmington, Del.) “The largest, single controllable expenditure in a plant is maintenance, and in many plants the maintenance budget exceeds annual net profit.” Despite the report’s age, the findings that one-third of all maintenance expenditures are wasted due to unnecessary or ineffective maintenance practices remains valid.
In the process industry, instrument maintenance accounts for about 20% of all maintenance spending, and thus is a prime target for cost-reduction programs. (See Maintenance costs in typical chemical plant graph.)
Among many instrument maintenance activities, the following five offer the most potential for saving money using smart instrumentation and asset management software.
Commissioning and start-up —Commissioning instrumentation is a time consuming activity and usually involves three technicians—one in the field to locate devices and input signals, one in the rack room to verify field devices are connected to the right terminations and control system I/O devices, and a third at the control system operator interface verifying each input signal’s correctness.
Bruce Johnson, engineering and technical manager at Noltex LLC (LaPorte, Tex.) says, “Using ‘real-world’ tests, we proved to management that using smart instrumentation and asset management software could reduce commissioning and start-up activities by 30%. In the end, we shaved 43% from the expected three-week schedule.”
Calibration —Periodic calibration is one of the most time-consuming of all instrument maintenance activities. Much of the time is spent in precalibration planning and post-calibration documentation. Personnel must look up calibration procedures for each device—and there can be thousands of them in a large processing plant.
An instrument’s test details are keyed into a handheld communicator, and the technician conducts calibration testing at the instrument’s physical location. Upon completing the calibration, forms must be filled out and filed. Technicians often spend from one to four hours per device (average is about 95 minutes) using generally accepted calibration procedures. Asset management software automates and streamlines precalibration planning and post-calibration documentation activities. This translates into timesaving, improved work accuracy, and better utilization of resources.
Maintenance Practices —According to ARC Advisory Group (Dedham, Mass.), 65% of all maintenance is corrective (reactive) and an additional 30% is a preventive. According to presentation made by Quist and King in Knoxville, Tennessee in 1998, only 5% of current maintenance activities are conducted as a result of predictive analysis, yet predictive analysis maintenance costs only one-half as much to perform as corrective maintenance. Despite the potential savings, there remains a time-honored practice of either waiting for things to break, or conducting scheduled maintenance, thus holding maintenance costs unnecessarily high. Intelligent field devices and asset management practices can help achieve predictive maintenance activities.
Troubleshooting —Hank Sinclair, formerly a site maintenance process leader at Dow Chemical’s Texas Division (Freeport, Tex.) says, “We found that only 36% of the trips to the field [to troubleshoot reported problems] resulted in any corrective action taking place.” In 1997, Kellogg Brown & Root (Houston, Tex.) reported “up to 85% of [troubleshooting] time is spent on dead-end roads.”
Maintenance engineers at major oil companies estimate that “no problem found” trips to the field cost between $60 and $100 per trip. David Montgomery, process engineer at Solutia’s Decatur, Alabama facility, estimates labor savings due to reduced “ghost chasing” at $35 to $65 per incident. Companies simply cannot afford to chase problems that don’t exist. With information from smart field devices and the use of asset management software, personnel can learn what, if anything, is wrong and determine a corrective action plan before leaving the maintenance shop.
Documentation —Based on field studies, out of 30 minutes it takes to initialize a device, 15 minutes are spent documenting the parameters. More than half of a 95-minute calibration effort is spent completing the documentation.
“Automated documentation of instrument tests saves an average of $132 per device per year. That is a reduction of 40% compared with costs before we implemented our asset management solution,” according to ACS Dobfar (Tribiano, Milan, Italy) automation manager David Splendore.
Asset management software supports automatic documentation and is more accurate than hand-written reports.
The essence of predictive maintenance is to save time, avoid unexpected equipment failures, and better manage plant assets through use of early warnings (devices alerts) and easier, faster access to device health information. Automatically recorded problems and associated work activities reduce or eliminate paperwork, freeing technician time.
Process industry suppliers offer a variety of elements for deploying HART (Highway Addressable Remote Transmitter) or FOUNDATION fieldbus implementations of asset management technology. For example, a number of instrument and valve manufacturers provide proprietary configuration and diagnostic software to complement their devices. Software for multi-company device configuration and/or calibration is available from companies such as Applied System Technologies (Ft. Lauderdale, Fla.), Beamex (Marietta, Ga), Blue Mountain Resources (Stone Center, Pa.), Fisher-Rosemount (Eden Prairie, Minn.), and Fluke (Everett, Wa.).
Establishing an asset management program can be done all at once or in small steps. If no smart devices are in use, start replacing older, more critical instrumentation with fieldbus devices.
Where smart devices already exist, it’s possible to obtain information using a handheld communicator and upload the information into a personal computer (PC) running asset management software. Modems can also be used to facilitate communication among a limited number of individual devices and a PC running asset management software. Until permanent multiplexers are installed, modems connected to or installed in a PC with asset management software provide the ability to collect smart instrumentation information.
In a HART-based installation, ultimately multiplexers are installed. Each multiplexer is the equivalent of 32 individual device modems, enabling direct, continuous, online access to the field-based information by an asset management program installed in any PC or laptop computer.
In many cases, proprietary control systems can be retrofitted with termination panels incorporating multiplexer boards, making it possible to pass status information from a variety of field devices through the control system to the asset management software.
Eliminating process variability is the goal, achieving that goal requires healthy equipment and asset management can help keep equipment healthy. Asset management technology can help provide that all-important knowledge.
|Stuart Harris is a member of Fisher-Rosemount’s Performance Technologies Group in Eden Prairie, Minn.|