From WWII Bombers to Smart Factories: The Data-Driven Evolution of Maintenance

Manufacturing is rapidly changing due to competitive pressures, labor shortages, supply chain issues and economic/trade challenges. Manufacturers must be more efficient, get more from their equipment and improve Overall Equipment Effectiveness (OEE). Balanced, data-based maintenance approaches reduce unplanned downtime and optimize the use of scarce resources. Predictive maintenance, condition monitoring and "run to fail" strategies are now common terms, but these ideas aren't as new as they seem. In fact, their roots trace back to World War II, when the Royal Air Force’s (RAF’s) Coastal Command confronted a surprisingly similar problem: how to maximize the uptime and usage of complex, resource-intensive machines – their airplanes.

World War II and the Battle of the Atlantic: a data-driven approach

In 1942, during the back-and-forth of World War II’s Battle of the Atlantic, the British faced a significant challenge: U-boats had increased the number of Allied ships being sunk, and there were insufficient resources to counter the threat. The British devised a creative and unique solution: gathering scientists from a wide range of fields into an Operational Research Section to design various approaches to combat submarines.

One of the most effective potential tools in the battle was the long-range bomber. Unfortunately, commanders assigned most to the strategic bombing campaign against mainland Europe, leaving very few to fight the U-boats. The Operational Research Section focused on both the tactics and the availability of the airplanes – they developed more effective combat techniques, but also examined ways to maximize flying time and increase the number of planes available for missions.

When maintenance backfires: lessons from bomber planes

As the team analyzed the data, they reached a counterintuitive conclusion: scheduled maintenance (preventative maintenance) was reducing, not increasing, service levels and availability. This was for several reasons:

• Regulations required squadrons to keep 75% of their planes ready for operational duty, so crews held back flyable planes while waiting for the others to be serviced.

• Long wait times for maintenance.

• Slow maintenance throughput due to bottlenecks (some departments were overloaded while others were not fully used).

• Long maintenance times due to overly detailed procedures (servicing parts with very low probability and/or impact of failure).

• Component failures increased, rather than decreased, shortly following maintenance.

What does this have to do with today’s maintenance approaches? Many of the challenges the RAF faced 80 years ago affect manufacturing today. The need to:

• Improve OEE and reduce unplanned downtime.

• Optimize scarce labor and resources.

• Avoid servicing non-critical, low-failure rate components.

• Improve inventory utilization and reduce the inventory of non-critical spare parts.

Data-driven policies that are still relevant today

The RAF’s Operational Research Section implemented several policies and processes which today are being “rediscovered” in factory and warehouse maintenance, including:

• Use actual production data to address bottlenecks and optimize personnel/resource scheduling.

• Analyze failure data to implement condition-based monitoring and/or predictive maintenance.

• Implement longer (rather than shorter) maintenance intervals when justified by data.

• Take a “run to fail” approach for non-critical components with very low failure rates.

We have a major advantage over the RAF’s Operational Research Section because today’s facilities have advanced systems and tools. They make it much easier to gather and analyze equipment data, and then apply the appropriate maintenance approaches to minimize unplanned downtime and maximize the effectiveness of maintenance resources. Smart sensors enable monitoring of critical machine failure indicators. Industrial networks simplify the process of building and scaling controls architectures that connect sensors to control systems, analysis platforms, and the cloud. The IIoT also enables the quick and easy transfer of data to where it is needed. It’s important to remember, however, that today’s data-based, effective, and proactive maintenance strategies are partially built upon the RAF’s Operational Research Section's ground-breaking work in 1942.

Sources:

“Blackett’s War,” Stephen Budiansky, Knopf Doubleday Publishing Group, 2013
Mike Busch, Sport Aviation Magazine, March 2011, “The Waddington Effect”