Tech Update<br> No-brainer maintenance tools
"Production is the prima donna of the plant floor," grouses one grizzled maintenance engineer. "We scare people when we come out on the plant floor because a visit usually means it's costing the company money."
Hope springs eternal, though, and several factors are converging to change corporate perceptions of maintenance personnel as the bad news bears of food manufacturing. Asset management continues to be a hot button in the executive suite, helping to expand the view of maintenance as a contributor to profitability, not strictly a cost. Like all technology, the tools to improve maintenance are following the trend toward simplified use at lower prices. And maintenance engineers are getting better at selling financial managers on the payback from maintenance investments.
Before executives fixated on asset management, software companies promoted computerized maintenance management systems (CMMS) to better organize maintenance programs and generate the financial data to demonstrate where maintenance costs were going and what the return was. Now, software vendors market CMMS as an asset management and lifecycle management tool.
Engineers always recognized CMMS's value as an organizational tool, but it takes the soul of a bean counter to appreciate return on maintenance spending. Fortunately, maintenance professionals, particularly the younger ones, are adding cost-justification to their skill sets, making the execution and rationale for CMMS more transparent.
"Some of the younger engineers who are computer literate were very interested in implementing CMMS when I started working with Smithfield Foods in 1997," recalls Oscar Solis, a field specialist with AssetPoint, a Greenville, S.C., software firm. Solis helped a Gwaltney and a Smithfield plant implement AssetPoint's TabWare CMMS package that year. Since then, the corporation has made it a standard offering, with more than 20 facilities using it to track work orders, parts inventories and performance criteria.
Key performance indicators (KPI) are a management mantra, and maintenance KPIs can't be measured without the tracking information that CMMS provides. "There's always one guy at the plant who has a pretty accurate feel for the number of work orders and the availability of parts, but management doesn't want gut feel: they want numbers," Solis says. "CMMS brings better control and a snapshot view of maintenance expenditures."
Mike Shackelford, applications manager at Seattle-based West Farm Foods, concurs. Since implementing Datastream's 7i CMMS software in 2002, management perception of maintenance has shifted from a cost center to a profit center, he says. Shackelford joined the company, which operates a dozen dairies in the Northwest, in 1988 as a maintenance engineer. He attests to the need to embrace KPI reporting and a business model in plant maintenance. An earlier CMMS effort involving Datastream's MP2 package failed because maintenance workers didn't buy into the program. To make sure they understood the payback from logging jobs and recording use of parts, the dairy hired a consulting firm to train workers in best practices in maintenance.
"Build a core team of individuals from purchasing, accounting, inventory and maintenance so that they take ownership of CMMS and not view it as just another software program," advises Solis, based on his experience at Smithfield. Once the team is in place, organizational issues can be addressed:
n How will the system be set up to handle work orders, parts inventories, emergency responses?
n How will responsibilities and authorizations be separated to maintain the integrity of the process?
n What procedures will workers be trained in to execute in posting work orders, logging tasks, etc.?
n What elements of legacy systems will be incorporated, and how should they be mapped (purchase orders to an accounting package, work-time reporting to human resources, etc.)?
"The (replacement parts) stores are where the savings are easiest to quantify, and it takes six to eight months to have the data needed to analyze the true dollar-value there," he adds. As the plant moves away from a "reactionary" approach to predictive maintenance, CMMS will document a decrease in emergency repairs. "If my PM is strong, the number of work orders should go down because there are fewer breakdowns," says Solis. That was the pattern at West Farm, where costs fell 5 percent after an initial run-up in the first six months of implementation, according to Shackelford.
Driving down intelligenceAs routine work begins to supplant crisis mode, managers can begin flirting with predictive maintenance, a level of sophistication that has been stubbornly out of reach for food and beverage plants. Condition-based monitoring tools such as vibration analysis, shock pulse signals and oil analysis are part of the predictive maintenance arsenal, and they are winning users in this industry.
While power plants, petroleum processors and other industries where unscheduled downtime would be disastrous have made use of predictive maintenance for years, affordable technology for equipment found in food and beverage plants simply has not been available. That may be changing, however, with the introduction of a new intelligent drive from Bosch Rexroth. Called the IndraDrive, the digital-drive system features firmware that enables the drive to not only conduct self-diagnostics but also conditions in any attached mechanical systems. Friction conditions in roller sideways and spindles, rigidity of gears and play in gearing and spindles are among the conditions that can be monitored and interpreted.
Unlike conventional servo drives, the units feature an integrated PLC to deliver "decentralized intelligence," according to Rexroth's Daniel J. Throne, business manager for the food & packaging industry. The drive acts as an "intelligent sensor," performing plant-specific maintenance functions and reporting measurement values to the machine controls for interpretation. The drive is always able to return to the basic default functions built into it.
The further machine intelligence can be driven down into devices, the more likely early warnings will be received to trigger maintenance measures to prevent machine breakdowns. Motor signals are filtered, and integrated sensors enable the drive to collect parameters such as speed, current, temperature, DC-link voltage, winding temperature, rotor position and speed and motor current. If mechanical systems are operating within tolerance parameters established in a reference curve, scheduled maintenance can be skipped. If true deviation is occurring, on the other hand, preventive steps can be taken.
The ability of suppliers to dumb down predictive-maintenance technology is making it more accessible, according to Larry Goodenow, technical services manager at SPM Instrument, Marlborough, Conn. "Instead of simply providing measurement data that must be analyzed by someone with special training, devices are supplying answers," says Goodenow. SPM manufactures hand-held units that use the shock pulse method for monitoring ball and roller bearings, vibration severity monitoring for machine imbalance and other faults, and devices that employ the evaluated vibration analysis method (EVAM). All provide instantaneous red-yellow-green status reports to give users immediate feedback on machine condition. Unless root-cause analysis is desired, that may be enough.
"If you're concerned about what the problem is, EVAM is great," he says. "If you just want to know when a motor is going bad, it's more technology than you need. That's often the case in a food plant where you just have blowers, pumps, conveyors and small motors that aren't worth rebuilding and are really disposable." An Ohio donut plant is making use of EVAM, but for the most part food manufacturers simply want to know when a piece of equipment is approaching failure so that replacement can be planned during a scheduled downtime.
Interpreting data from sophisticated tools can be an issue at even the largest food and beverage facilities. Recognizing that, Rockwell Automation is emphasizing remote monitoring of its XM Series modules for condition monitoring. Introduced in 2002, XM collects the vibration-analysis, energy-consumption measurement and other monitoring data from devices made by its Entek division through a plant's control network architecture, effectively automating data collection by creating an I/O Bus. "The XM Series brings the benefits of distributed monitoring and protection to plant equipment that, due to technology cost, normally receive little or no predictive maintenance attention," according to Ralph DeLisio, business manager, integrated condition monitoring, support and maintenance services at Rockwell.
Major breweries are the only food and beverage application so far for XM, though any processor who would lose costly batches if unexpected downtime occurred could benefit from XM, DeLisio says. However, "training people in condition-based monitoring is expensive," and even large breweries have limited engineering staffs to undergo such training. As a result, "one of the things we've beefed up at Rockwell is the ability to offer this as a service," he says, with Rockwell technicians interpreting the data remotely.
Rockwell recently expanded the types of XM modules that can be distributed to machines in a facility, adding vibration monitors that detect different signal frequencies than previous monitors and temperature sensors that are more attuned to energy spikes. Rockwell also is expanding the types of networks on which XM will function, with Profibus being added to DeviceNet, Ethernet and Modbus options soon.
"The speed and spectrum of the heat and vibration signals that can be analyzed continue to be enhanced," DeLisio notes, and costs continue to decline. But conveyor bearings and small motors common in food plants do not warrant continuous monitoring. Periodic measurement with handheld devices becomes a more cost-effective option.
Prices for handheld devices are crashing. Wavetek Meterman Test Tools in Everett, Wash., recently introduced a data acquisition package priced under $200. The 38XR DMM can log temperature, frequency, duty cycle, current draw and voltage supply. Data can be exported to an Excel spreadsheet for reporting, charting and analysis. According to Wavetek's Terry LaBrue, small food companies are among the instrument's early users, including Northwest Wild Foods, a small Burlington, Wash., firm that processes preserves from wild berries.
It's uncertain how useful the data from those handhelds prove to be. What is certain is that maintenance technology is increasing in sophistication while decreasing in cost. That presents an enormous opportunity for the engineers who know how to apply it within their organizations.
For more information:
William Russell, AssetPoint-TabWare, 846-679-3462, email@example.com
Daniel J. Throne, Bosch Rexroth Corp., 847-645-3749, firstname.lastname@example.org
Ralph DeLisio, Rockwell Automation, 513-576-6151, email@example.com
Larry Goodenow, SPM Instrument, 860-295-8241
Terry LaBrue, Wavetek Meterman Test Tools, 425-446-5070, firstname.lastname@example.org