In brief:
- The benefits of increasing wrench time are substantial and the impact is felt organization-wide.
- To increase wrench time, companies must focus on eliminating wasted time.
- Some elements of wrench time may be beyond the control of the planner or technician.
Wasted time is the enemy of wrench time. When maintenance technicians spend excessive amounts of time gathering tools and parts, arranging specialized equipment, searching for information or traveling to job sites, their value-added work time is constrained. In an ideal world, once a planner assigns work, the technician should be fully equipped to focus on productive repairs and replacements, without undue lag time.
Realistically, it is impossible to achieve 100% wrench time. Often it ranges between 25% and 35%, although in industries with remote and highly distributed assets, the rate can be even lower. However, it is possible to find wiggle room in the rate by studying maintenance practices, implementing work planning and process improvements, and leveraging the benefits of asset management software and technologies.
The significance of wrench time
Industrial organizations aim for high maintenance productivity and efficiency in their efforts to secure safe and reliable asset performance. One example is Thomas & Betts (T&B, www.tnb.com), whose 220,000-square-ft steel structures manufacturing facility in Hager City, Wisconsin, makes custom-engineered, Meyer-branded steel tubular poles used for the transmission of electrical power. Seventy-five million pounds of product are produced per year, according to Jeff Boigenzahn, plant manager.
Fifteen of the plant’s 220 employees are in the maintenance organization. Boigenzahn believes their wrench time currently averages 30%, with the balance of the time spent on work planning, gathering parts, performing preventive maintenance tasks, and looking at schedules. “When something goes down, it takes time to find the root cause, diagnose the problem, determine the solution, and then if we don’t have the part on hand, we’ll go get it,” says Boigenzahn.
The ideal amount of wrench time is extremely variable. In energy utilities, it depends on the network. “At a power generator in an urban environment, less time is required to collect the necessary tools and parts, so the wrench time there is higher than it would be in a rural power district company,” says Kristian Steenstrup, vice president and research fellow for Gartner (www.gartner.com). “Maximizing wrench time is significantly more important for transmission and distribution (T&D) than a generation utility because there is more preparation time and travel for T&D, and the proportion of wasted time could be much greater.”
Figure 1. Technician adjusts the PLC controls on a Clayton Industries boiler.
Similarly, maintenance service providers tend to have a high percentage of travel time. Clayton Industries (www.claytonindustries.com), established in 1930, manufactures industrial steam generator systems for customers worldwide (Figure 1). Service contracts ensure that the purchased boilers receive preventive maintenance in accordance with the manufacturer’s specifications, and that emergency repairs are performed in an expedited fashion.
“Our technicians supplement our customers’ own maintenance organizations to ensure that their capital investment is protected,” says Larry Smith, vice president and national service manager for Clayton Industries. He oversees 40-45 field service technicians, 13 service branches, and two service depots throughout the United States and Canada. The technicians follow a 65-point PM checklist step by step, and they are available around the clock to respond to emergencies.
Strategies to eliminate wasted time
To increase wrench time, companies must focus on eliminating wasted time. At Clayton Industries, travel time and the lag time waiting for parts are minimized by fully equipping the service technicians. “We carry a highly stocked service vehicle for each technician in order to optimize their time. If a needed part is not on the truck or at the branch site, we’ll ship it overnight from one of the service depots,” says Smith. “The branches also help each other; parts are driven between branches or taken to an airport if necessary.”
In addition to common parts, the trucks are equipped with safety apparel and equipment, tools such as combustion analyzers, water treatment chemicals, and everything required for lockout/tagout, confined space, OSHA and other regulations.
Technician skills and maintenance strategies are the focus at T&B’s plant. “While we already have some of the lowest maintenance costs in the division, we would definitely like to raise our wrench time rate. A lot of it depends on the knowledge and experience of the individual technicians. When they know what needs to be done, less planning time is required,” says Boigenzahn.
The age of the equipment influences work assignments. The Hager City plant has been in operation since 1971 and some of its equipment is more than 40 years old. “For our older equipment, we rely on individuals who have become per-machine experts. For newer equipment, our technicians are generally trained at the time of installation,” explains Boigenzahn. Aging machines are subject to parts availability constraints. At some point, replacements are more timely and cost effective than repairs. “It takes longer to source older parts than we would like. We track the costs and the time it takes to get the machines up online, and we use that information to decide when to replace the equipment,” he adds.
[pullquote]Suiting up in personal protective gear necessarily takes time away from wrench time. “We have a very good safety record, especially in maintenance,” says Boigenzahn. “We make sure that all the right protective gear is used, especially for work with switchgear and electrical boxes.”
Steenstrup recommends tackling wasted time in the three phases of work:
- Preparing for the job: GIS and GPS mapping tools and automatic vehicle locator (AVL) devices enable more sensible routing and schedules. Having an inventory system connected to planned and unplanned maintenance forecasts ensures tool and parts availability. Likewise, effective coordination ensures that specialized equipment is available at the right time and place, whether it’s a cherry picker, lift truck, or personal protective gear.
- On the job: The ability to view the location of assets through GIS and accessing an accurate work history, detailed work instructions, and exploded parts view while on the job minimizes wasted time and ensures the job is completed correctly in one visit. “The likelihood of rework is increased when the equipment, condition, or parts are not as expected,” explains Steenstrup.
- After the job: Results should be recorded accurately and promptly after the repair, including what transpired, the condition of the equipment and whether it is degrading. The data is useful for costing and historical purposes. Efficient routing to the next destination prevents lag time. Steenstrup also recommends measuring job performance and rewarding those who work efficiently. “The quality of data recorded after an event is measurable and should be rewarded when done well. Rework is a sign of a lack of planning and penalties can be used to avoid it,” he says.
External factors play a role
Some elements of wrench time may be beyond the control of the planner or technician. For instance, PM tasks are subject to machine availability. “If there’s a hot job, then maintenance can’t get in there right away,” says T&B’s Boigenzahn.
Figure 2. Technician reads the gauges on a Clayton Industries boiler.
Clayton Industries has similar concerns (Figure 2). “Most often our schedule interruptions are customer-driven,” says Smith. “If there is a production change that interferes with scheduled maintenance, we’ll reschedule the PM to a later date. If a boiler breaks down, it becomes our top priority.”
In some respects, wasted time may be ingrained in the culture. Steenstrup recalls a mining company that experienced a significant number of in-service equipment failures. “Management suspected that the truck operators were not particularly concerned about breakdowns because they could sit in a warm coffee shop during repairs rather than driving around the frozen tundra,” he explains. “Work was reprioritized to address PMs before repairs, and the operators were incentivized for hours of operation in order to keep the equipment working as much as possible. Ultimately, the culture changed from breakdown/repair behavior to preventive maintenance behavior.”
Using software to manage time
Asset management software provides numerous opportunities to increase wrench time. It produces efficiencies in work planning, scheduling, and dispatch processes. It allows the proper allocation of skilled resources and availability of parts, tools, and specialized equipment. It provides mobile access to asset information and produces reports that improve decision making.
T&B’s steel structures facility uses asset management software to facilitate PM scheduling, manage tool crib inventory, and generate purchase requisitions to maintain adequate stock levels. The company is evaluating from a corporate standpoint whether to roll out the software to all plants and how to upgrade the software and information to be more sophisticated. “We’d like to keep up with the latest and greatest enhancements, like mobility, although in some respects we don’t think we’re a big enough facility to really need it even though it would be nice to have,” says Boigenzahn.
At Clayton Industries, a proprietary system is used to track the company’s customers, assets, and service schedules. It is also used to determine what parts to keep in inventory. “We look at the historical customer base and determine what parts are needed to service normal wear and tear as well as the most common emergency work,” says Smith. “We maintain a lot of inventory but our service contracts are a big commitment.”
The spreadsheet-oriented tools are used outside of the company’s MRP system, but Clayton Industries is in the process of implementing an ERP system that will consolidate and automate its work scheduling, inventory management, and reporting capabilities. “The ERP implementation will allow the tracking of a lot more information, ensure the PMs are performed on schedule, and support all invoicing. We’ll get monthly reports showing when PM schedules are late and when it’s time for service contracts to be renewed,” say Smith. “The inventory management side of the new system is also much better than what we currently have,” he adds. “It will take our inventory levels down to the truck stock area and we’ll be able to leverage min/max levels, automatic reorders, and other capabilities that we have been lacking. All of this will improve our wrench time. We are excited about getting the ERP up and running this calendar year.”
Asset management software further reduces wasted time when assimilated with other technologies. For instance, it incorporates AVL and GPS data to form route schedules, which are integrated with maintenance work plans or customer service requests. It integrates the parts catalog and bill of materials, as well as equipment rental and booking processes with planned and unplanned work. On the job, integrated mobile devices provide remote access to asset information and accelerate data entry, eliminating paper-based recordkeeping.
One of the most promising developments is the emergence of remote-controlled asset management, which eliminates travel time. This is particularly important to plants with distant or hard-to-access assets.
Active approaches improve results
Gartner’s Steenstrup recognizes seven valid maintenance strategy approaches that range from tactical to strategic: run to failure, time-based preventive, usage-based preventive, condition based, predictive, reliability centered, and financially optimized. “I don’t see these as competing strategies but rather a progression of complexity, maturity and benefit,” he says. “Which approach is used depends upon the equipment and its condition.”
For example, run to failure ensures that equipment is not over-maintained, but it assumes a changeover can be made at the point of failing without catastrophic consequences to health and safety. Condition-based maintenance is not good for equipment with particularly long lead times, such as equipment located in-ground or requiring specially-sourced parts, because once the threshold is crossed, maintenance may be too late. In these instances, predictive forecasting is better.
“I recommend building up a repertoire of the seven maintenance strategies and matching the strategy to the type of equipment and scenario,” says Steenstrup. Granted, not all companies are in a position to apply the highest-level strategies because it requires integrating operational technology and information technology.
Clayton Industries’ customers are encouraged to prevent the need for wrench time. “All equipment is vulnerable to failure, but the failure rate is higher when there is no preventive maintenance. We recommend initiating preventive maintenance and holding to the manufacturer’s recommended PM schedule as closely as possible,” says Smith. “This will increase the longevity of the equipment and ensure less unscheduled downtime and nonproductive time, because loss of production as we all know means loss of revenue.”
At T&B’s plant, intelligence-based decisions are improving wrench time. “We are using our software to track maintenance costs and help determine when it’s time to install new and improved equipment. At the moment, we have three key pieces of equipment in transition: a new cutting machine is coming in; automated welding on the long seam is being built; and an overhaul is scheduled for this summer,” says Boigenzahn. “These are major improvements, but there’s always something else to do; it’s just like owning a home.”
To prevent downtime, the plant depends on its employees to report when they see something going wrong. “We make sure that all maintenance cards are turned in. The cards get prioritized and the equipment is fixed before a bigger problem can occur,” explains Boigenzahn.
For plants looking to improve their wrench time, Boigenzahn recommends listening to your employees who run the machines and also to your maintenance personnel. “Use their guidance, in addition to your software’s data, to make good, solid decisions,” he says.
Find the wiggle room to leverage the benefits
The benefits of increasing wrench time are substantial and the impact is felt organization-wide. Greater workforce utilization and efficiency reduces maintenance costs and rework, and it improves uptime. It also enables strategic corporate objectives. Reinvesting wrench time savings in reliability initiatives will further extend the duration between failures and disruptions, positively affecting performance overall.