Transitioning from reactive to predictive maintenance (PdM) is arguably the single most powerful way to reduce maintenance costs while improving reliability, overall equipment effectiveness (OEE) and return on assets (ROA). Most maintenance professionals have at least passing familiarity with predictive technologies such as oil analysis and vibration, temperature, power and ultrasonic monitoring, and many have implemented one or more. Most plants have some form of computerized maintenance management system (CMMS), and some have made a considerable investment in reliability-centered maintenance (RCM). Now the big boss is saying the entire plant must embrace Lean.
Yet many maintenance departments remain mired between reactive and preventive activities, unable to free enough management or technician time (or mindshare) to collect accurate data, organize and correlate it, and use the results to reduce wasted activity and prevent failures.
Moving from reactive to predictive is a culture change. It requires thinking and acting differently, which takes new priorities, retraining and fundamental shifts in daily activities. Short of wholesale outsourcing, a plant can’t buy its way to predictive. But one small class of tools can do the most to facilitate the change: mobile computers.
The foundation of efficient maintenance is timely, comprehensive, accurate data on machine condition and maintenance activities. With it, you can stay on top of changing priorities, improve workforce efficiency and build the repair histories necessary to track failure modes, quantify the costs of problem equipment, evaluate preventive maintenance (PM) procedures, and support decisions about PdM programs.
Mobile computers foster comprehensive, accurate data collection by minimizing the number of steps and opportunities to introduce errors as data flows in and information flows out of the CMMS. Danny Justice, building maintenance lead at Gordon Food Service (GFS), Brighton, Mich., works in a 380,000 sq.ft., distribution center that ships more than 500,000 cases weekly. “With 6.5 miles of conveyor and a large fleet of mobile equipment, our 15 mechanics stay quite busy,” he says. “We have been using Intermec 700 handhelds loaded with the Maximo Mobile Work Manager for more than three years now. The devices allow our mechanics to record all kinds of data while on the floor. Before the implementation of the handhelds, our mechanics had to wait for one of three shop PCs to record into Maximo by hand.”
The comprehensive, accurate data also helps justify maintenance expenditures. “At one auto plant, unionized employees have been cooperating for seven years,” says Richard Padula, president, Syclo (www.syclo.com). “They don’t want to track the time, but now they can prove the work that gets done. Management thinks that people are sitting around and it wants to cut 10% —tracking allows maintenance to show management what they’re getting for their money.”
Barcode scanning capabilities can simplify inventory control and equipment identification. “The mechanics pull their own parts here at GFS,” Justice says. Each part has a barcode label printed on it for easy scanning into the device. “Our four unlocked, open parts rooms maintain a 99% accuracy rate almost every month. All of our equipment is labeled, and makes for easy scanning of equipment numbers. The days of guessing, ‘what equipment are they referring to?’ are gone.”
Along with more complete, accurate information, mobile systems can improve the timeliness of data transfer. Southern Nevada Water System (SNWS), Las Vegas, has two treatment plants and 12 maintenance technicians (Figure 1). They were buried in paperwork before turning to PDAs. “I might hand a maintenance tech a month’s worth of preventive maintenance work orders, which could include hundreds of tasks,” says Jeffrey Deitch, SNWS business systems analyst. “He might just bite at this work load day to day and, at the end of the month, come back with a stack of paper and say everything is done. If you want more timely input on the status of your equipment, you need input more than every 30 days.”
SNWS already had an Avantis.Pro asset management system, so Deitch installed the mobile PDA option. “With the PDA, instead of receiving a stack of paper work orders for the day, technicians get a PDA loaded with their work assignments,” he says. “At the end of the day, they hand in the PDAs.”
In a wastewater plant, a spill or inadvertent release of polluted water can trigger as much a $15,000 EPA fine. Maintenance people need to know when conditions are ripe for a release so they can immediately tend to the problem. The city of Xenia, Ohio, installed an HMI/SCADA system from Indusoft (www.indusoft.com) which includes wireless PDAs. Everyone from managers to maintenance techs can see key data and receive alerts, at the plant or at home. Since the system was installed, there have been no regulatory violations as a result of slow maintenance response to alarms. The entire system paid for itself the first time Xenia responded in time to avoid an EPA fine.
The case for wireless
Wireless data transfer can take timeliness to a new level. Most handheld devices today use a cradle or docking station, which charges the PDA’s battery, downloads information from the PDA to the CMMS, and uploads new work orders. Technicians have to cradle their devices at the beginning, the end and sometimes during a shift. Going wireless eliminates the cradle.
At Philadelphia Newspaper’s 681,000 sq.ft. plant in Philadelphia, maintenance manager Ken Smith chose wireless instead of docking stations. The plant already had a CMMS from Mapcon (www.mapcon.com), so Mapcon installed a wireless PocketMaint software application for $6,000. Adding wireless to the plant, Smith says, cost about $4,000. Thirteen employees — Smith’s maintenance team and six environmental staffers — received Hewlett-Packard iPaqs for another $13,000, bringing the total cost of the wireless upgrade to $23,000.