Mean time to repair/restore (MTTR) is the maintenance metric that summarizes the historical time taken to make necessary repairs and adjustments to return equipment to its desired operational state. In other words, “Fix it fast, fix it right.” When I ponder the nuances of MTTR, though, I think about motorsports pit crews, for whom “fix it right” is more important than “fix it fast.” The message is, “Take the time to do it RIGHT or don’t do it at all.”
Improving pit-stop MTTR includes many moving parts, some of which are visible, some not. The crew chief has overseen, directed, coached, and prepared the pit crew and their entire support team for world-class pit stops (MTTR) for months. But there’s more.
Performing routine preventive maintenance work consistently is key to pit-stop success. Removing and replacing tires, refueling, adjusting, and gathering information must be accomplished right the first time, every time. For various reasons, though, pit stops differ. Handling the unpredictable elements efficiently and effectively is also a top priority. Understanding and preparing for the known and potential failure modes is also key.
Designing for the most efficient and effective pit stop is a collaborative process among racecar engineers, fabricators, pit-crew members, tool makers, and parts-room management. Racecar components are redesigned and modified to make their changeovers more efficient and effective. Tools such as race guns (impact wrenches) and jacks are also redesigned and modified to make them perform better and last longer. Fuel cans are modified to dump approximately 11 gallons into a vehicle’s fuel cell in less than six seconds. The right parts “fit for service,” when needed, is also essential.
Mistake-proofing is another key to reducing and sustaining the lowest MTTR possible. Visual cues help crew members install the right tires and locate the jack in the optimum location every time. Lug nuts painted bright colors also help the tire changers see these threaded fasteners through the brake dust that accumulates on the wheel.
Still, it’s not just the over-the-wall-pit-crew-member tasks that must be aligned for a successful pit stop. The pit-support team, behind the wall, positions tires for the tire changers; has fuel cans filled and weighed at the ready; assures tangle-free air hoses; passes refreshing drinks to the driver; and much more.
One of the biggest variables in pit-stop MTTR is the human element. Although crew members may have their own preferred methods of performing a task, clinging to those respective methods could turn a pit stop into a failure. Accordingly, during routine pit stops, each crew member must perform his or her individual task as an interdependent part of the overall team. Every position, step, grab, pull, and place is measured and performed according to specific procedures that coordinates with, facilitates, or precedes another crew member’s task.
While “fix it fast” is an essential element in pit stops and reducing MTTR, the more important element is “fix it right.” With practice and experience, the speed of each task and reduced pit-stop time will come. But if the work isn’t done right, the first time, every time, premature failures are imminent. And a race team’s goal is to have no unplanned pit stops between the routine ones.
A race team’s crew chief and each department leader must work together to plan and execute pit stops with flawless human and equipment performance. That’s why leadership and teamwork is the foundation for reducing MTTR in motorsports. The same holds true in today’s plants and facilities.TRR
ABOUT THE AUTHOR
Bob Williamson is a long-time contributor to the people-side of the world-class-maintenance and manufacturing body of knowledge across dozens of industry types. His background in maintenance, machine and tool design, and teaching has positioned his work with over 500 companies and plants, facilities, and equipment-oriented organizations. Contact him directly at 512-800-6031 or email@example.com.
Tags: reliability, availability, maintenance, RAM, MTTR, KPIs, leadership, workforce issues, training and qualification