- 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.