Chapter 17 – The OM Blog by Heizer, Render, & Munson

OM in the News: Agentic AI Revolutionizes the Factory

It’s 4 a.m. at a large automotive parts plant. The night-shift supervisor freezes as the dashboard flashes an alert: a critical spindle is vibrating out of tolerance. In the old world, he’d wait for maintenance to evaluate and decide. But today, an AI agent has already paused the line, checked service records and called the right technician—before he even takes a step toward the control room.

That’s the new reality for many manufacturers facing a stubborn obstacle: the ever-widening gap between data and decisive action. Now, a new class of digital entities is changing that equation. AI agents powered by decision intelligence are beginning to sense, reason and act across the manufacturing ecosystem, cutting decision latency from minutes to milliseconds.

Think of AI agents as the digital nervous system of a modern factory. They continuously sense what’s happening across machines, people and systems, then respond intelligently without losing context. Across the manufacturing stack, they’re quietly reshaping work for every role:

On the shop floor: Agents merge operations and information technology (IT) data to give operators real-time context. They can recommend optimal machine parameters, trigger tool-change schedules, balance workloads across lines or alert technicians before deviations escalate. Maintenance teams can use agents to predict component wear and plan interventions that don’t interrupt production– a topic in Chapter 17.

In production and quality operations: Agents help supervisors and quality staff detect process drift early. They analyze sensor data, images and process variables, suggesting immediate corrections or automated parameter tuning. In continuous manufacturing, this can mean fewer rejects and less rework, which we discuss in Chapter 6.

In ERP and planning: Agents connect production, procurement and finance systems. A planning agent (see Chapter 14) can run simulations of “what if” scenarios, what happens if a supplier shipment is delayed or if energy costs spike and recommend production adjustments.

Across the supply chain: Agents can constantly monitor inventory, supplier performance and logistics signals. When a potential shortage or delay is detected, they are able to trigger contingency workflows such as redistributing available stock, recommending alternate suppliers or rescheduling deliveries–see Chapters 11 and 12.

To sum it up: “Tomorrow’s factories won’t just inform — they’ll decide,” writes Industry Week (June 12, 2026).

Classroom discussion questions:

Summarize what AI agents can do in a factory setting.
How does agentic AI have the potential to change the manufacturing operation?

OM in the News: AI’s Big Manufacturing Productivity Gains

The efficiency and productivity improvements AI can deliver through automation and digitalization will help bridge manufacturing’s workforce gap, writes Industry Week (March 13, 2026).

Similar to the PC revolution decades ago, all signs point to AI following suit with enhanced productivity and profitability. Productivity soared when PCs became interconnected across organizations. Manufacturing will see the same breakthrough with “embedded AI”—to help ease workforce bottlenecks with specific solutions. On the shop floor, for example, predictive-maintenance AI (see Chapter 17) can analyze sensor data to forecast equipment failures and avoid labor-sapping downtime.

AI vision systems (Chapter 7) can catch defects on production lines at a pace beyond human capabilities and without the repetition-induced fatigue and employee turnover. Collaborative robots (cobots) and automated mobile robots transport material and can assist with assembly and repetitive operations. AI’s coding capabilities extend to numerical control and other industrial equipment, speeding up setup time and productivity in hard-to-fill technical positions.

The interaction of embedded AI, agent-based AI, and machine learning across different areas of an organization holds the greatest promise in solving long-term labor shortages. AI can already let a customer snap a photo of a damaged part and identify it for replacement. Its real power will manifest when AI can also determine the part’s inventory status and locations, establish shipping terms and timing, add the part to the procurement queue to replenish once it’s sold, alert engineering that a design change for a chronic defect may be in order, and propose alternative designs.

Here is a current example involving AI across systems: the big semiconductor company AMD is using generative AI to track down the root cause of delivery delays, simplifying complex supply chain interactions to transform a complex, specialist-dependent, labor-intensive manual process into faster issue resolution and better decision-making. The system cuts the time needed for what was a 14-step process taking 20-30 minutes by 90%, saving more than 3,100 staff hours a year.

Also coming soon to these intelligent product recommendation engines is an ability to parse what can be 50-page tender documents to extract multiple configurable products for sales quotes. That not only saves time, but also enables junior staff to handle work that has previously required experienced hands.

Classroom discussion questions:

What can AI do to improve a procurement system?
What does “embedded AI” mean?

OM in the News: Brain Injuries for Crew and Passengers at Delta

Why is maintenance (see Chapter 17) one of the 10 Operations Management decisions around which our text is based? If you ever fly, today’s post will explain why.

Employees are suing various airlines for toxic fume incidents

Delta Air just announced that it is replacing “additional power units” (APUs) on more than 300 of its popular Airbus A320 jets to stem cases in which toxic fumes have leaked into the air supply and led to health risks for passengers and crew.

The move is one of the most aggressive efforts by a major U.S. airline to address what in recent years has increasingly become a hidden hazard of modern air travel, reports The Wall Street Journal (Sept. 25, 2025). The APU is a third engine that sits in the plane’s tail and is used to generate electricity and pump air into the cockpit and cabin when the two primary engines aren’t running. (For example during taxiing). A leak can also contaminate the air even when it isn’t in use.

A fume event typically occurs when oil leaks into the engine or APU’s compression chamber and is vaporized at extreme heats, releasing neurotoxins and other chemicals into the cockpit and cabin air. Fume events have been surging on the Airbus A320 family and have led to brain injuries and other illnesses in both crew and passengers.

Over the past year, APU-related fumes on Delta’s A320 jets have led to emergency diversions and abandoned takeoffs, pilots donning oxygen masks and passenger vomiting.

The increase in incidents follows changes to maintenance requirements that Airbus began approving from 2017, which allowed airlines to regularly send aircraft back into service after a fume event had occurred.

Two years after the change, Airbus issued a “good practices guide” to help airlines mitigate APU-driven fume events. That included extensive weekly visual inspections to the power unit and a suggestion that pilots wait 3 minutes after turning on the APU so it might start working properly.

Airbus also suggested a second option–that airlines operate flights with the APU air supply turned off (removing air conditioning on the ground)–if conducting maintenance might cause disruption to their flight schedules.

“Corrective maintenance action can be planned at a better opportunity,” Airbus wrote in 2019. It also reminded airlines that the precautions for mitigating fume events were only an optional guide. But internal maintenance documents show that Airbus was aware of fumes-related issues since 2001.

Classroom discussion questions:

What is the difference between “preventive” maintenance and “breakdown” maintenance?
What are some of the hidden costs of ignoring the maintenance on the APUs?

OM in the News: Ford Breaks Record—Of Safety Recalls

Ford has recorded more safety recalls in the first six months of 2025 than any car company ever has in an entire calendar year, reports The Wall Street Journal (July 12-13, 2025).

Ford just recalled 850,000 pickup trucks and SUVs because of a potential fuel-pump failure. A bad fuel pump could result in the engine stalling while a driver is operating the vehicle.

Last month, the firm said it would need to fix 200,000 all-electric Mustang Mach-E SUVs after receiving complaints from the government about customers being unable to open their doors as a result of the vehicle’s 12-volt battery dying, including cases where children were trapped inside. “There was no way for me to get inside my car without jumper cables,” a driver in Houston wrote in an April complaint. The person had to call emergency services and break into the car.

Also this year, Ford said it would need to fix nearly half a million 2016-2017 Explorer SUVs to prevent door trim from falling off. The issue was potentially creating a road hazard for other drivers.

In January of 2025, Ford paid $65 million to the government as part of a settlement over violations of auto-safety laws, specifically over a delayed recall of 600,000 vehicles with defective rearview cameras. As part of the agreement, the automaker said it would spend an additional $45 million to improve internal systems for tracking safety issues.

Ford and its CEO have staked out improving quality as a priority for the automaker. Improving quality will also help to reduce the billions of dollars Ford spends every year on warranty claims and safety recalls. The company hired a quality czar in 2022, and it has tied 70% of executive annual bonuses to quality. It said it has significantly improved product quality in recent years, with four new models winning accolades from a recent J.D. Power study on quality. The company has more than doubled its team of safety and technical experts and expanded testing on critical systems, such as vehicle powertrains, steering and braking.

Overall, recalls across the auto industry have been rising, with more than 1,000 recorded in 2024, compared with 800 a decade earlier.

Classroom discussion questions:

What quality tools in Chapter 6 of your Heizer/Render/Munson text could Ford employ to decrease defects?
Discuss Figure 17.1 in the context of Ford’s problems.

Guest Post: The Dangerous State of Air Traffic Control in the U.S.

Temple U. Professor Misty Blessley brings up a very timely OM issue-air safety.

Newark Liberty International Airport (EWR) has recently experienced multiple air traffic control outages, during which radar and communication systems used to track aircraft temporarily went offline. These disruptions have lasted up to 90 seconds in several incidents. Flights into and out of EWR have decreased by approximately 35% as a result.

When an outage occurs, air traffic controllers may issue a ground stop, essentially a pause in departures, similar to a real-life game of “red light, green light”—for planes awaiting take off. While Module D of your Heizer/Render/Munson textbook introduces queuing theory, the real-
time queues at EWR are available here. In practice, incoming planes may be directed into holding patterns that resemble stacked racetracks in the sky.

However, when radar and communication systems go dark, there’s no safe way to guide aircraft into these stacks or maintain proper separation. Once communication is restored, controllers must work through the resulting queues to safely sequence and clear aircraft for landing. Outages lead to flight delays and cancellations while also raising serious safety concerns. How can the skies be stabilized?

Modernize Technology – Many Federal Aviation Administration (FAA) systems still rely on outdated technology, including some that operate on decades-old hardware such as floppy disks. The federal government is actively working to modernize these systems by investing in updated
software, hardware, and communication networks.

Support and Expand the Workforce – During the recent incidents at EWR, some air traffic controllers have taken trauma leave, underscoring the high-stress nature of the profession. The U.S. has been facing a persistent shortage of qualified air traffic controllers, due in part to limited training capacity—currently, only one FAA facility is responsible for training controllers. With low acceptance rates and rigorous requirements, meeting demand has been challenging. However, efforts are underway, including the involvement of new schools, to expand training opportunities and help grow the workforce.

Classroom discussion questions:
1. In Ch. 17, Maintenance and Reliability is discussed and Ch. 6 covers Managing Quality. What lessons can be applied to make the skies safer?
2. What domino effects are likely to ensue once the plane has safely landed? What do you think can be done to attract more air traffic controllers?

Guest Post: Reliability of Bridges

Retired Temple U. Prof. Howard Weiss is the developer of the POM and Excel OM software that we provide free with our text.

On March 26, 2024 the container ship Dali crashed into the Francis Scott Key Bridge that spans Baltimore harbor. Ships had crashed into major bridges previously but in this case the damage was far worse than usual. The bridge collapsed into the harbor, 6 died, and, of course, travel across the harbor was affected.

The Dali was not even that large, with a capacity of 10,000 containers. (The largest container ships have a capacity of 24,000 containers). The obvious operational problem is that the bridge, which carried over 30,000 vehicles daily could not be used and the vehicles had to take either alternative routes. Reconstruction of the bridge began in January, 2025 but the detours will be needed until Fall, 2028.

The NTSB reported that Maryland did not conduct a test that would have identified structural risks for the bridge. After this incident, the NTSB indicated that 68 bridges that have commercial traffic in the U.S. needed to be inspected.

A recent study provided a list of the 20 bridges with the highest probability of having major damage due to being hit by a ship. The results of the top and bottom five in that list are displayed below along with reliability calculations in the shaded area.

operations management blog The table performs these computations for each of the 20 bridges for a 1- year period, a 10-year period and a 100-year period.

The single year reliability is simply = # of years minus 1 divided by # of years. For example, for the Huey P. Long Bridge, reliability is 16/17 = .9412. That is, there is roughly a 6% chance of an accident in any given year. From your Heizer/Render/Munson textbook (Ch. 17), the 10 year reliability is given by

Rs=R 1 ×R 2 ×R 3 ×…× R 10

And since the reliability each year is the same this is identical to R 1 ^10. Thus, there is roughly a 50% chance that in 10 years the Huey P. Long bridge will have an incident. The safest of the 20 bridges, the John Blatnik has a less than 1% chance of a major accident over 10 years. Similar computations are given for a 100 year period.

Classroom Discussion Questions
1. What actions can be taken to reduce the chance of a major accident?
2. If the number of years between collisions can be increased by 10% (rounded up) how does that affect the 10 year reliability for the Long and Blatnik bridges?

Guest Post: Electricity Power Lines and Operations Decisions

Prof. Howard Weiss survived the recent hurricane that hit Florida and shares his thoughts about losing power.

The two recent hurricanes, Helene and Milton, have devastated power lines in many places but especially in Florida and N. Carolina. Florida Power estimates that underground lines fared 12 times better than lines that were overhead during the hurricanes.

There are two situations utilities face, depending on whether it is a new installation or a change from aboveground to underground. In either case there are several OM factors that are discussed in your textbook that are relevant when deciding whether to use overhead lines are below ground lines.

Fixed costs In general, underground lines require trenches and manholes which are more expensive to build than erecting pylons/poles for overhead wires. Also, underground wires require special insulation. The cost of installation can vary depending on the locality. Underground lines cost 5-10 times as much as aboveground lines–$1.5 to $3 million per mile compared with $285,000 to $800,000 per mile for above ground lines.

The first overhead lines and poles were built in 1844 and at that time underground lines were tried but they failed.

Variable costs The major variable costs are for maintenance and repair. Underground lines are more difficult to maintain or repair. The major direct cost to consumers is the cost of being without electricity. Ultimately all of the costs will be borne by the consumers.

Capacity Above ground cables have roughly 6 times as much capacity as underground lines.

Reliability While below ground lines are not 100% reliable, they are more reliable than overhead lines. Above ground power lines can be felled by wind, ice storms, falling trees and damaged by squirrels. Below ground power lines can be washed away or corroded along coastal areas due to storm surges. In Winter Park, Florida, where 80% of lines are underground, 98% of customers had power during Hurricane Milton.

Lifespan Aboveground lines have twice the lifetime, 70 years, compared with belowground lines.

Risks Aboveground lines can spark and cause fires. Pacific Gas & Electric paid $55 million after its power lines started a destructive brush fire. Also, sometimes power needs to be shut off to prevent any fires.

Aesthetics Clearly, belowground lines lead to a more pleasing appearance than overhead lines.

Classroom Discussion Questions
1. Does your community have underground or overhead wires or both?
2. What analysis could be done to make the decision between overhead or underground lines?

OM in the News: Maintenance Issues and Dead Workers

Wayne Rothering was a few months away from retirement when a machine killed him. He worked on a laminator line at a large Wisconsin furniture factory. He stopped the conveyor and stepped inside the line to fix a torn roll of paper. Behind him, powered rollers that fed 5-foot-by-6-foot slabs of fiberboard into the system continued to spin. As Rothering worked, the rollers caught hold of a board on the conveyor and propelled it into his back. Rothering was crushed to death.

Ashley Furniture paid a fine in a settlement with OSHA after Rothering’s death but didn’t admit fault

He was among hundreds of U.S. workers to die over the past decade in mishaps that a regulation known as “lockout/tagout” is supposed to prevent. The concept is simple: Before an industrial machine can be serviced, an employee must shut it down and place a lock over its power source. If that isn’t possible, the employee should place a tag telling co-workers to leave the machine off.

Lockouts are designed to prevent employees from being hurt by machines that start unexpectedly. Every year, an average of 85 people are killed and 364 suffer amputations. Violations related to the lockout standard are the most common safety citations issued by OSHA.

Incidents usually happen because employers fail to implement adequate safety measures, writes The Wall Street Journal (Oct. 4, 2024). “They take shortcuts, figure it’s too much trouble to lock it out, or they get pressure to keep productivity moving,” said a former OSHA exec. Companies often minimize downtime with alternatives that allow machines to remain powered during minor servicing.

Sometimes machinery is still operating when workers enter dangerous areas. Two years ago, Leily Lopez-Hernandez was blowing dust off a pizza company’s cooling machine. She went beneath the machine and was decapitated. After, OSHA fined the firm $2.8 million for 29 violations, 17 of which were deemed “willful”—meaning an employer purposefully disregarded regulations or acted with indifference to safety.

“It’s easy to blame the working person for failing to heed a warning or follow a procedure, but we know that’s going to happen, not because they are lazy or stupid, but because there are competing motivations,” said an industry attorney. “If the employer emphasizes production above all, so will the employee.”

Classroom discussion questions:

You are the operations manager at a manufacturer. What can you do to prevent such injuries and deaths?
What is the role of the Occupational Safety and Health Administration (OSHA)?

OM in the News: The Mercedes-Benz EV on Fire

It took just seconds for an underground South Korean residential parking lot to be engulfed in flames. The culprit: a Mercedes-Benz EQE electric vehicle that had not been charging.

The blaze incinerated dozens of cars nearby, scorched a further 140 vehicles and forced hundreds of residents to emergency shelters as the buildings above the parking lot lost power and electricity. Nobody died, but the fire took eight hours to extinguish. Cars with internal combustion engines are more likely to catch fire than EVs. But when EVs do burst into flames, the rechargeable lithium-ion batteries get hotter and the fire takes longer to stamp out, writes The Wall Street Journal (Aug. 8, 2024).

In recent years, General Motors recalled tens of thousands of its Chevrolet Bolts in the U.S. over risk of battery fires. Hyundai pulled roughly 80,000 electric sport-utility vehicles after roughly a dozen caught fire. Last September, a Nissan Leaf ignited while charging in Tennessee, and the fire required more than 45 times the water needed for a gas-powered-car fire to be extinguished.

Automakers have grown more cautious about EV launches amid modest demand. Sales of fully electric models in the U.S. rose 6.8% through the first half of the year, a sharp deceleration from near 50% growth in 2023.

The perceived risk of EVs is particularly acute in tightly packed South Korea, a country about the size of Indiana with 52 million people. Outdoor residential parking lots are relatively uncommon. The nation’s ubiquitous high-rise apartments often feature underground parking, where firefighters must contend with restricted access. The country had already been on edge about battery-related fires, after a blaze at a lithium-battery factory in June that killed nearly two dozen people.

In recent days, LG Display recommended that employees at its main factory complex park their EVs outside. The country’s main international trade association, whose offices are located in central Seoul, said it would accelerate plans to relocate EV charging ports to its aboveground lot. One of the country’s largest telecommunications firms, KT, has held discussions about barring EVs from parking underground.

Classroom discussion questions:

Which of the 10 OM decisions in your Heizer/Render/Munson text deal with this issue?
What are the OM implications of the South Korean fire?

OM in the News: AI in Manufacturing

Manufacturers are increasingly evaluating and adopting AI solutions to leverage their data, writes Industry Week (Feb. 13, 2024). Here are some key areas that stood out in how manufacturers are adopting the technology:

Quality control enhancement: AI can improve manufacturing quality control through vision systems trained on images and videos, accurately detecting complex product defects. Real-time monitoring identifies issues promptly to prevent future defects, and AI’s continuous learning enhances defect detection. (See Ch. 6)

Supply chain visibility: Manufacturers deal with enormous amounts of data in their operations, and the integration of AI technology allows real-time observation, quicker trend identification and more accurate forecasting to meet demand effectively. AI algorithms analyze historical sales data, market trends and external factors, enabling more precise demand forecasts and aligning production and inventory levels. In logistics, AI optimizes routes by analyzing transportation costs, delivery times and traffic patterns, enhancing efficiency and cost-effectiveness. The strategic use of AI in the supply chain offers benefits like improved visibility, increased agility and better planning, enhancing overall resiliency and responsiveness. (See Ch. 11)

Energy efficiency and resource utilization: Companies are using AI to optimize energy consumption and resource utilization in manufacturing processes. These capabilities analyze real-time data from sensors, production equipment and other sources to identify patterns and trends in energy usage. This can inform predictive recommendations to optimize energy consumption, reduce waste and enhance overall resource efficiency. (See Supp. 5)

Predictive maintenance improvement: The use of AI in predictive maintenance enables a shift from reactive to proactive strategies, leveraging data-driven approaches. AI algorithms analyze real-time data to predict maintenance needs and failures. AI identifies patterns on the factory floor, detecting anomalies and potential malfunctions. This proactive approach minimizes unplanned downtime, extends equipment lifespan and allows manufacturers to optimize resource allocation through scheduled service activities during planned downtime, enhancing overall productivity and reducing costs. (See Ch. 17)

The use of AI in manufacturing operations in coming years is expected to accelerate. Investment in AI technologies is forecast to rise among 96% of companies by 2030.

Classroom discussion questions:

How will AI become a common tool for operations managers?
Using a search engine, describe a real company example for these applications.

OM in the News: Maintenance Really Does Count

When Ural Airlines Flight 1383 to Siberia suffered a technical fault with its hydraulics a few months ago, the pilots decided to divert to a closer airport. Then they discovered the defect meant the aircraft was rapidly running out of fuel and needed to land quickly. The plane, with 165 people onboard, eventually made a successful emergency landing in a farm in southern Russia. The Airbus A320 jet remains there, fenced in and under security, with Ural agreeing to pay rent for a year to the land’s owner–and then harvesting the jet for parts.

The episode is among a surge in aviation-safety incidents recorded in Russia last year, and an indication of how Western sanctions are hindering the country’s ability to source spare parts and conduct proper maintenance, writes The Wall Street Journal (Feb.5, 2024). (See Chapter 17 in our text). Some 74 air safety incidents were logged in Russia last year, up from 36 in 2022. The data show an incident occurred 9.9 times in every 100,000 departures in 2023, compared with 5.0 in 2022 and 4.5 in 2019. The incidents include repeated instances of engines catching fire or becoming inoperative during a flight, rubber landing-gear tires bursting during landings, and malfunctioning flaps leading to diversions.

Sanctions imposed after Russia’s invasion of Ukraine have cut off that country’s access to Western aircraft manufacturers, banning the provision of spare parts, maintenance support, critical software updates and more. “The sanctions imposed on Russian airlines have significantly impeded the maintenance of aircraft airworthiness and their technical condition,” said one industry expert.

Russia is particularly exposed to shortages of landing gear and brakes, and has had to send aircraft to Iran for maintenance. And a lack of technological know-how in repairing wheels and separate issues with low-quality deicing chemicals have led to safety incidents. Meanwhile, a shortage of parts for simulators limit Russia’s ability to train new pilots and run required refresher courses.

The deterioration of Russia’s aviation safety record is undoing decades of work by Russia’s airlines to modernize their fleets and turn around a reputation for questionable safety. That effort started in the early 2000s, when Russian airlines spent billions of dollars buying brand-new Boeing and Airbus jets to replace aging and less-reliable Soviet-era aircraft. The splurge left Russia with one of the biggest aircraft fleets in the world– a total of 1,031, most built by Airbus and Boeing. Russia’s total operational fleet is forecast to halve by 2026.

Classroom discussion questions:

What are the two types of maintenance issue that Russia airlines face?
How does Figure 17.2 (Overall System Reliability) apply in this case?

OM in the News: Toyota’s Production Halted Due to Insufficient Disk Space

Managers, as we note in Chapter 7, appropriately spend a huge amount of time developing the proper process. But the perfect process is useless if not maintained (See Ch. 17 in your Heizer/Render/Munson text). Toyota was recently reminded, in a very expensive way, that lack of maintenance or improper maintenance can destroy even a well designed process.

It appears that Toyota’s 14 Japanese factories all shut down for about two days in late August due to a production order system malfunction caused by failure to maintain adequate computer disk space.

According to Toyota, its Japanese factories and their 28 assembly lines were halted due to “some multiple servers that process part orders” becoming unavailable and causing Toyota’s production order system to malfunction on August 28. The situation caused production output losses of roughly 13,000 cars daily, which threatened to impact exports to the global market.

The problem began during maintenance work on August 27. Toyota said: “During the maintenance procedure, data that had accumulated in the database was deleted and organized, and an error occurred due to insufficient disk space, causing the system to stop. Since these servers were running on the same system, a similar failure occurred in the backup function, and a switchover could not be made.”

A Reuters report claimed that the Toyota saw a third of its total production shut down until August 30. It said it restored its production order system on August 29 after transferring the data to a larger-capacity server. The malfunction happened while the parts ordering system was being updated. This shutdown directly impacted the company’s production ordering system so that no production tasks could be planned and executed.

The announcement is a blunder for the world’s top-selling automaker, which failed to ensure that mission-critical operations would be able to function, reports ArsTechnica (Sept. 6, 2023).

But Toyota affirmed that the outage was “not caused by a cyberattack.” The car vendor’s cybersecurity has faced scrutiny over recent years. Toyota shut down the same 14 Japanese factories in February 2022 due to a supplier getting hacked. But August’s outage may be more financially detrimental to Toyota than the 2022 event since domestic output was up 29 percent in the first half of this year, the first such increase in two years. Toyota was also hacked in 2021 through a US manufacturing parts subsidiary and at least three times more in 2019.

Classroom discussion questions:

How were operations impacted by this shutdown?
Was this a case of “preventive” or “breakdown” maintenance?

Guest Post: Three Kinds of Maintenance

Professor Howard Weiss, who created the free Excel OM and POM software for our text, provides a fresh view of maintenance.

CNN recently been reported that “the Philippines closed the whole country’s airspace for 6 hours in May to replace malfunctioning electrical equipment.” The shutdown was necessary because there have been a number of breakdowns in the air system which led to thousands of passengers being stranded.

The difference between preventive maintenance and breakdown maintenance is described in Chapter 17 of your Heizer/Render/Munson textbook. Preventive maintenance involves monitoring equipment and facilities along with performing routine inspections and service to keep equipment and facilities reliable. Breakdown maintenance occurs when preventive maintenance fails and equipment/facilities must be repaired on an emergency or priority basis.

Of course, many companies employ both types of maintenance. For example, Suncor refinery in Colorado is currently undergoing planned maintenance of one of its plants. But last December breakdown maintenance was necessitated by a fire on Christmas eve. The Philippines maintenance is more or less a hybrid of the two types of maintenance described in the textbook. It is not breakdown maintenance because there is not a current failure in the system. It is not preventive maintenance in that they are not performing routine inspections and service although it is like preventive maintenance in that it will be scheduled ahead of time rather than occurring during a breakdown.

Planned maintenance provides several advantages. It offers the possibility to account for an expected drop in supply. For example, airlines going to and from the Philippines have the opportunity to adjust their schedules to avoid or minimize the effects of the shutdown. Similarly, Russia provides 4 days of planned maintenance on one of its pipelines. Citizens still have fuel because the stockpiled inventory will be used.

Planned maintenance also provides the opportunity to inform customers or neighbors about possible side effects such as noise or odors from the maintenance, fires flaring from stacks, and, of course, possible service disruptions. The City of Bakkerskloof, South Africa, had time to warn residents about water discoloration after the maintenance of its water unit and to tell residents that trucks would be coming around with water during the maintenance period. Frontier Communications in Beckley WV had time to warn residents that 911 service would be shut down on land lines for 4 hours during preventive maintenance and that customers should use their cellphones during that period for 911 calls.

OM in the News: Two Looks at the Importance of Maintenance

Two recent Wall Street Journal articles cite examples of how many aspects of maintenance costs are not noted in standard accounting procedures (see Figure 17.4 and related discussion in your Heizer/Render/Munson text). Preventive maintenance involves monitoring equipment and facilities, along with performing routine inspections, to keep them reliable.

The fire overtook the town of Paradise within hours, leaving residents unable to escape.

Here is the first (from WSJ, Aug.26-27, 2022): Across the country, transmission lines are among the oldest parts of the electrical grid, Many were constructed in the years after World War II as Americans moved from cities to suburbs, built homes wired with wall sockets, and bought electric appliances. Some transmission lines are even older, developed shortly after the turn of the 20th century to replace gas lamps and candles at a time when electricity was still something of an experiment. For example, PG&E Corp.’s transmission line was built in 1921 in the Sierra Nevada mountains.

On Nov. 8, 2018, just before sunrise, strong winds pummeled a power line scaling those mountains north of Sacramento, Calif. A hook hanging from a century-old transmission tower broke, dropping a high-voltage wire that spit a shower of sparks setting dry brush aflame. The Camp Fire, named for the road near its place of origin, burned for 17 days, destroying 150,000 acres and 19,000 structures. It killed 84 people. PG&E pled guilty in 2020 to involuntary manslaughter charges. It said that inspections revealed the need for more than 250,000 repairs across the system. But they had not taken place. PG&E’s lack of preventive maintenance cost lives.

The second article (from WSJ, Sept. 2, 2022) involves the U.S. Army: The Army said its maintenance personnel installed the wrong parts on some of its 400 Chinook helicopters, prompting military officials to ground the entire fleet. The Army experienced at least seven incidents of fuel leaks, four of which involved engine fires. The parts in question, types of seals known as O-rings, weren’t faulty, just not the ones that were supposed to be installed. The Army has taken steps to correct the maintenance error and inspect helicopters suspected of having the incorrect O-rings, which the U.S. government purchased for 11 cents each.

The helicopters have ferried American soldiers and equipment on battlefields since the helicopter’s debut in 1961. The military had no estimate for when the aircraft would begin to return to service.

Classroom discussion questions:

Who in the PG&E organization is responsible for this maintenance failure?
As an Army Officer in change of Chinook helicopter maintenance, what changes would you make?

Guest Post: The Atlanta Airport Plane Train

Prof. Howard Weiss shares his teaching ideas with us monthly.

Atlanta’s Hartsfield Airport is the busiest airport in the world in terms of both passengers and aircraft, having served over 75 million passengers in 2021 and having 707,661 aircraft movements in the same year. In order to move passengers from one concourse to another the airport uses an automated people mover (APM) dubbed the “Plane Train” that is operating 60 feet below the airport. The plane train system consists of 11 trains which each have 4 cars. Together they have the capacity to transport 10,000 passengers per hour from one concourse to another. Daily ridership is 200,000 passengers.

The trains run in a loop as displayed below covering 2 miles in each direction. A four year $331 million project is currently underway on the Plane Train and 3 more trains are being added that will increase the capacity to 12,000 passengers per hour by 2024. This will reduce the maximum waiting time from the current 108 seconds to 90 seconds. There currently are 123 employees who work three shifts.

Chapter 17 of your textbook discusses maintenance and reliability. There are two train maintenance stations with 5 total bays located below ground. Preventive maintenance is performed during the night time when the number of passengers requiring transportation between terminals is greatly reduced. Given the daytime number of passengers requiring transportation from one station to another it is imperative that the trains are always operative. Therefore, maintenance is performed on all 11 trains every night with tasks ranging from minor to major. In addition, the tracks need to be maintained, so the system is shutdown Wednesdays at 1am for track maintenance. Furthermore, to maintain reliability the system has 12 cars which serve as backups to the 44 cars in the system.

The De Mar case study in your Design of Goods and Services chapter (Ch. 5) notes that De Mar uses performance measures and compensation that incorporate customer satisfaction. Similarly, for the Plane Train there are incentives to keep the trains operating. The maintenance teams will receive a bonus if they maintain 99.5% reliability. But if reliability does not reach 90% the workers will not be paid a bonus.

Discussion Questions –

What will be the productivity change with respect to the additional 3 trains that are going to be added?
The Plane Train operates 24 hours per day. What is the efficiency of the system?