Reliability – The OM Blog by Heizer, Render, & Munson

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: 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?

OM in the News: Measuring the The Best and Worst Airlines

There’s been enough drama in the past year to impact U.S. airlines quality rankings. An Alaska Airlines blowout grounded dozens of planes. There was a failed JetBlue-Spirit merger and Spirit’s bankruptcy. A summer tech outage crippled Delta. Southwest Airlines faced investor pressure and said it’s switching to assigned seating. All while planes remained packed and air traffic congested.

Delta took the crown again in The Wall Street Journal’s 17th airline scorecard (Jan. 23, 2025), standing out in nearly every category. This is Delta’s 4th consecutive win and 7th in eight years. It prides itself on reliability and customer service—it displays this and other accolades on stickers near its cabin doors—and commands a premium for it. There’s a reason those Delta tickets often cost more. Southwest finished a mere point behind Delta, with Alaska in third. In the ratings cellar? Frontier. Spirit placed 8th and American Airlines finished 7th.

The 9 major U.S. airlines are ranked on 7 equally weighted operations metrics: on-time arrivals, flight cancellations, delays of 45 minutes or more, baggage handling, tarmac delays, involuntary bumping and what the Transportation Department calls passenger submissions (which are mostly complaints).

Delta finished first in on-time arrivals and was the only airline in the ranking to exceed 80%. It canceled far fewer flights than in 2023, giving it the lowest cancellation rate besides Southwest. “It’s a testament to our people, along with the resiliency, reliability and efficiency we’ve purposely built into our operation, that we canceled fewer than 1% of our scheduled flights and improved or held steady in nearly every category,” said Southwest’s COO.

Delta’s weak spot: bag handling. The airline’s mishandled bag rate trailed those of Allegiant, JetBlue, Frontier and Southwest. Frontier, the airline that draws you in with $19 tickets and piles on fees galore, finished at or near the bottom in all but two categories, dropping a spot in on-time arrivals and extreme delays from 2023. It did best in baggage handling, where it ranked third.

The overall scores fall off fairly dramatically after Delta and Southwest. Third-place finisher Alaska finished nine points below Delta, Allegiant 11.

Classroom discussion questions:

In Chapter 6 of your Heizer/Render/Munson OM text, we discuss TQM. Which of the many tools are used in the quality ranking metrics?
What would you do if you were Frontier’s operations manager?

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?

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?

Guest Post: Process Design–Drug Dispensing Machines

Prof. Howard Weiss, developer of our POM and Excel OM software, provides his insights monthly.

Table 7.4 of your Heizer/Render/Munson textbook lists examples of the use of technology in health care and other service industries. One technology in health care that is often used in hospitals is the computerized medication cabinet also known as the automated dispensing cabinet. (See page 215 for an example). These drug cabinets offer a number of advantages over the former non-powered old-school medication carts, but can lead to serious problems when the wrong drug is selected. Unfortunately, hospitals are not required to report when wrong drugs are administered so we do not know the depth of the problem. (A nurse in Tennessee was recently prosecuted for wrongful death when she selected the wrong drug).

The current process requires the nurse to enter the first 3 letters of the drug that they want. Safety advocates want at least 5 letters to be entered to reduce or avoid confusion and the cabinet makers are currently in the process of making the change to require 5 letters. While a 5 letter requirement seems better than 3 letters from a safety standpoint, requiring more letters leads to problems other than safety. This will require that nurses can correctly spell names of difficult pharmaceuticals. Sometimes these drugs are needed in chaotic emergency situations and using 5 letters instead of 3, while intended to improve safety, will slow the process down. Of course, three letter names can cause spelling problems, for example, if the nurse is unsure whether the drug begins with “ph” or “f”.

The general goal when dealing with dispensing drugs is to have as many layers of safety as possible. This is sometimes called the Swiss cheese model. The holes in Swiss cheese do not generally align so having enough pieces of Swiss cheese will prevent a mistake from going through all of the holes. The 5 letter requirement is a better slice of cheese than the 3 letter requirement.

This Swiss cheese approach of adding layers for safety is similar to web sites requiring a code sent by text to be entered in addition to entering your name and password. The CDC has essentially been using a Swiss cheese model for COVID protection, as seen in the figure.

As a final note on reliability, many hospitals still maintain the old-school carts as a backup in case of a power failure.

Classroom discussion questions :

What industries, other than healthcare, use a Swiss cheese approach?
If requiring 5 letters is better than requiring 3 letters, wouldn’t requiring 6 letters be better than 5 letters?

Guest Post: The Tesla Recall

Prof. Howard Weiss, recently retired from Temple U., shares his stimulating insights monthly on our blog.

Tesla is about to recall 135,000 automobiles, reports The Wall Street Journal (Feb. 2, 2021). Recalls occur after delivery of an item to a customer and as noted in Chapter 6’s “Cost of Quality” section in your textbook, their external failure costs can be extremely expensive. In particular, this recall means that the direct costs to Tesla will include the “cumbersome physical repair” (according to Tesla); the cost of the computer chip that needs to be replaced; the cost of reimbursement for the 23,000 owners who paid out of pocket for the repair prior to the recall; and the cost of informing Tesla’s service centers and owners about the recall. Your text also notes that there may also be a loss of goodwill or possibly liability costs.

The Tesla recall has to do with the touch screen control. Its failure can impact many different features, including backup cameras, defog and defrost controls, turn signals, heat and air-conditioning. Tesla claims that the touch screen should last 5-6 years. This is analogous to the Mean Time Between Failures (MTBF) in Chapter 17’s discussion of Reliability. But the National Highway Traffic Safety Administration (NHTSA) expects the touchscreen to last “at least the useful life of the vehicle.”

Tesla, of course, is not the only automobile manufacturer to experience recalls. According to NHTSA, from 2000 to 2019 there have been 14,791 vehicle recalls in the U.S. affecting roughly 680,000,000 vehicles. Over 90% of the recalls were for safety reasons whereas the other recalls were for non-compliance with federal standards. Manufacturers voluntarily initiated 80% of these recalls, while the remainder were instigated by the NHTSA.

Classroom discussion questions:

Have you been affected by the recall of any product?
What will be the major cost to Tesla for this recall?

OM in the News: NASA’s “Failed Mission” Probabilities

NASA is working with Elon Musk’s SpaceX to redesign part of the fuel system for the company’s Falcon 9 rockets and then will demand at least 7 successful unmanned flights before allowing astronauts on board. With routine flights ferrying U.S. astronauts to the orbiting international space station slated to begin in fall of 2019, the agency has raised new questions about potential hazards and longstanding NASA safety standards, writes The Wall Street Journal (Jan.18, 2018). Ending current U.S. reliance on Russian capsules for crew transportation may “require decisions to accept a higher risk” on next-generation U.S. systems than anticipated, says NASA.

NASA’s statistical limit for a “failed mission” remains 1 in 55 launches, despite several years of intense development, NASA expenditures of about $5 billion and significant additional investment by the two companies bidding for contracts–Boeing and SpaceX. That limit applies to mission failures in which the vehicle doesn’t reach the space station but the crew uses emergency procedures to survive.

NASA’s statistical standard for crew fatalities is no greater than one in 270 flights, though neither Boeing nor SpaceX is on track to meet that precise mandatory benchmark. By contrast, the global airline industry has achieved fatal accident rates for jetliners of 1 crash for several million flights.

System reliability is an old, but crucial issue at NASA. During the long era of the Space Shuttle, which I was proud to be a part of, mission reliability was set at 98%. This meant a critical failure was anticipated every 50 flights. And indeed, the first Shuttle exploded on flight no. 25 (Challenger), and the 2nd loss on flight 113 (Columbia) . The Shuttle program ended with flight no. 135, as a 3rd crash was viewed as unsustainable.

Classroom discussion questions:

Is 1 in 55 (reliability = .982) acceptable? Why?
Why is NASA seeking this alternative to Russia’s Soyuz ferrying rockets?

OM in the News: Samsung’s Battery Fix Gets a C Grade

To figure out what caused its Note 7 to catch on fire, Samsung put 200,000 phones through several different tests — To figure out what caused its Note 7 to catch on fire, Samsung put 200,000 phones through different tests

“After four months of testing over 200,000 phones,” writes The Wall Street Journal (Jan. 23, 2017), “what did Samsung determine caused its flagship Note 7 to catch fire?” The answer: Bad batteries. Two separate sets of bad batteries made by two different companies.

But what Samsung is still missing is its Tylenol moment. In 1982, Johnson & Johnson issued a massive recall after 7 people died from taking Tylenol products laced with cyanide. It led the company, and then the rest of the industry, to rethink pill packaging. Consumers saw the new seals as a mark of safety and protection. Samsung’s work on a seal that consumers can understand is still incomplete.

A quick recap: Note 7’s with 2 different versions of the battery–Samsung calls them A and B–were released last August. Soon after, some of the phones with Battery A started to burn up. Samsung recalled the phones, quickly replacing them with just Battery B models. Some of these phones started to burn up also, compelling Samsung to yank the phone altogether.

After erecting labs with 700 staff to test 30,000 batteries, Samsung has concluded that neither its hardware nor software was to blame. Instead, Samsung says the battery had issues.

Battery A had a design issue: There wasn’t enough room inside the battery for routine expansion of its component electrodes. Battery B had a welding issue caused by a manufacturing defect, which didn’t appear until production ramped up after Battery A was pulled from the market. (The resulting microscopic burrs poked through barriers inside the battery).

The core of the problem was that Samsung didn’t have the quality controls needed to identify the battery problems before they reached consumers.

Classroom discussion questions:

What responsibility might Samsung share in setting the specifications and requirements for the Note 7 batteries?
How can a phone maker prevent this kind of problem in the future?

OM in the News: Maintenance, Reliability and the McFlurry

Employees often just say the machine is down rather than reassembling it. Here an employee spills ice cream mix all over herself while trying to fill the machine.

Why is the McDonald’s McFlurry ice cream machine down again? “The interruption in ice cream, milkshake and McFlurry service is so widespread that it has spawned an avalanche of social-media complaints in the U.S. and abroad—and conspiracy theories,” writes The Wall Street Journal (Jan. 20, 2017).

“I’m convinced there’s no way an ice cream machine would be down all the time with no replacement or repair of the machine,” says one NY college student. After experiencing downed machines numerous times, another student had a meltdown, which she captured on Facebook. The video rant received 1 million views and 5,000 comments, many of which came from customers with the same complaint.

Fans say they love the texture of the McFlurry’s hard, crunchy candy and smooth, creamy, vanilla soft serve. (A 16-ounce McFlurry contains 930 calories and 128 grams of sugar, more than three 12-ounce cans of Coke, by the way.)

In the years since the McFlurry made its debut on the menu in 1998, it has garnered a cult following. And the cravings for it often come on suddenly and late at night. That may be part of the problem.

McDonald’s requires the machines to undergo a nightly automated heat cleaning cycle of up to 4 hours to destroy any bacteria in them. Getting the machines ready for the cleaning cycle is an 11-step process that involves combining a sanitizing mix with warm water, removing and rinsing 7 parts, brushing clean 2 fixed parts for 60 seconds and wiping down the machine with a sanitized towel. Once the heat cycle begins, it can’t be interrupted because the product is hot and under extreme pressure.

One survey found 25% of the restaurants weren’t serving ice cream because the machines were reported not to be functional. Downed ice cream machines is now the most common service-related complaint among McDonald’s customers.

Classroom discussion questions:

What are the OM issues here?
Have students had similar complaints? Suggestions?

OM in the News: Samsung’s Fatal Flaw

The Galaxy Note 7 Smartphone after it caught fire

“Big product recalls are never easy,” writes The Wall Street Journal (Oct. 24, 2016). In 1982, Johnson & Johnson recalled 31 millions of bottles within days of 7 people dying from cyanide-laced Tylenol. (J&J spent more than $100 million on the recall and product relaunch and was widely praised for its response). In 2009, Toyota recalled more than 8 million cars worldwide because of a faulty accelerator pedal, costing over $3 billion. And in 2015, 70 million Takata airbags were recalled in the U.S. alone. Consumers, however, are often willing to forgive mistakes if they believe the company is looking out for them and moving swiftly to address problems.

But, as the Journal‘s article “Samsung Recall’s Fatal Flaw” concludes, a rushed conclusion, based on incomplete evidence, forced the company to kill the Galaxy Note 7. A laboratory report last month said scans of some faulty devices showed a protrusion in Note 7 batteries supplied by Samsung SDI , a company affiliate, while phones with batteries from another supplier (Amperex) didn’t. It wasn’t a definitive answer, and there was no explanation for the bulges. But with consumers complaining and telecom operators demanding answers, the company felt it knew enough to recall 2.5 million phones. That decision in early September—to push a sweeping recall based on what turned out to be incomplete evidence—is now coming back to haunt the company.

Two weeks after Samsung began handing out millions of new phones, with batteries from the other supplier, the company was forced to acknowledge that its initial diagnosis was incorrect, following a spate of new incidents, some involving supposedly safe replacement devices. Worse, in China, where the company used only Amperex-supplied batteries in its Note 7s, the company dismissed reported smartphone fires as fabrications, arguing it was impossible for those batteries to have caused problems. Now, with U.S. regulators raising fresh questions, Samsung took the drastic step of killing the phone outright.

Classroom discussion questions:

What could Samsung have done differently?
Compare this recall with the 3 mentioned earlier.

OM in the News: RFID and Luggage Tracking

Radio chips are embedded in the tags being used at Las Vegas' airport ensure that suitcases move more quickly and accurately through the system. — Radio chips are embedded in the tags being used at Las Vegas’ airport ensure that suitcases move more quickly and accurately through the system.

One of my favorite new video cases for this edition is called Alaska Airlines: 20-Minute Baggage Process–Guaranteed! in Chapter 7. This is great example of process analysis and how OM can be applied in a way to improve customer service in the airline industry. And industry-wide, airlines show a steadily decreasing likelihood of bags going astray. Last year had the lowest rate of wayward luggage — 6.5 bags per 1,000 — in the past 12 years. Why?

Various advances in technology and bag-handling procedures deserve credit, including improvements over the years in the bar-coded tags and optical scanners that have long been in use for identifying and sorting checked luggage. Where bar-coded tags fall short is if the tag is wrinkled, smudged or torn, or not in line of sight of the scanner. If the tag is not readable, the bag can get lost without being noticed. Bar code readers have a “read rate” of only 80%- 95% of baggage tags.

“That is why the industry is intent on improving the tracking rate by looking beyond the 30-year-old baggage bar code,” writes The New York Times (Aug.23, 2016). They are adopting RFID tags that do not need to be seen to be read. Embedded chips can store travel information and need to be only close to radio scanners along the way for the bag’s progress to be recorded. Fliers can use travel apps to keep track of their bags. Delta is spending $50 million on the necessary scanners, printers and radio tags, which look little different from conventional bar-code tags. The system is now in place at all of the 344 airports into which Delta flies.

R.F.I.D. technology is hardly new, of course. But updating to the latest technology requires infrastructure changes that can be expensive and disruptive. And because most airports leave it to each airline to handle its own bag-checking system, the technology and procedures vary widely.

Classroom discussion questions:

What are the advantages of RFID over bar codes?
What does Alaska Air do to make sure bags arrive in 20 minutes?

OM in the News: The Boeing 787 Lithium Battery Explosions

The damaged battery case from a Japan Airlines 787

“Flaws in manufacturing, insufficient testing and a poor understanding of an innovative battery all contributed to the grounding of Boeing’s 787 fleet last year,” according to a new report by the National Transportation Safety Board (see The New York Times, Dec. 1, 2014). The report assigned in the starkest terms yet the blame for the 787’s battery problems.

The first battery episode occurred after a Japan Airlines flight landed at Boston’s Airport on Jan. 7, 2013 and was traced to one of its 2 lithium-ion batteries. The following week, a smoking battery forced an emergency landing in Japan, and prompted regulators to ban the jets’ flights until the problem could be resolved.

The NTSB found a wide range of failings among manufacturers and regulators. The battery’s maker, GS Yuasa of Japan, used manufacturing methods that could introduce potential defects but whose inspection methods failed to detect the problem. Boeing’s engineers failed to consider and test the worst-case assumptions linked to possible battery failures. The FAA failed to recognize the potential hazard and did not require proper tests as part of its certification process. The planes were allowed to fly again after Boeing instituted new safety features which added internal components to reduce the chance of overheating.

This was the first time large lithium-ion batteries were used aboard a commercial jet. But the NTSB investigation found that the manufacturing process allowed defects that could lead to internal short circuiting. GS Yuasa, the report said, “did not test the battery under the most severe conditions possible in service, and the test battery was different than the final battery design certified for installation on the airplane.” Boeing had initially determined that a battery cell might fail in 1 out of 10 million flight hours. Instead, by the time the two episodes happened, the 787 fleet in service had logged fewer than 52,000 hours. Both Boeing and GS Yuasa also underestimated the risks of a catastrophic failure. They relied on a single test, known as a nail penetration test, to simulate a short circuit to find out under what circumstances the battery might ignite.

Classroom discussion questions:

1. Why was Boeing’s reliability estimate so inaccurate?

2. How is this an OM issue?

OM in the News: Delta’s Unorthodox Scheduling System

Delta's Control Room — Delta’s Control Room

“The crew of Delta Air Lines Flight 55 last Thursday couldn’t legally fly from Lagos, Nigeria, to Atlanta unless they waited a day due to new limits on how much pilots can fly in a rolling 28-day period,” writes The Wall Street Journal (April 3, 2014). The trip would have to be canceled. Instead, Delta headquarters told the captain to fly to San Juan, which they could reach within their duty limits. There, two new pilots would be waiting to take the Boeing 767 on to Atlanta. The plane arrived in San Juan at 2:44 a.m., quickly took on fuel and pilots, and landed in Atlanta only 40 minutes late.

The episode, unorthodox in the airline industry, illustrates the fanaticism Delta now has for avoiding cancellations. Last year, Delta canceled just 0.3% of its flights. That was twice as good as the next-best airlines, Southwest and Alaska, and five times better than the industry average of 1.7%.

As it cut cancellations with a more-reliable operation, overall on-time arrivals improved and Delta has fewer delays. Managers in Delta operations center (featured in our Global Company Profile in Chapter 15) move planes, crews and parts around hourly trying to avoid canceling flights. How well an airline maintains its fleet and how smartly it stashes spare parts and planes at airports affect whether a flight goes or not. Delta’s new analytical software and instruments that can help monitor the health of airplanes and predict which parts will soon fail. Empty planes are ferried to replace crippled jets rather than waiting for overnight repairs. Typically the airline has about 20 spare airplanes of different sizes each day. About half are stationed in Atlanta and the rest spread around other domestic hubs and two in Tokyo.

Classroom discussion questions:

1. Why have Delta’s operations managers focused on cancelling fewer flights?

2. How does Delta’s fleet age (one of the oldest in the industry) impact this strategy?

OM in the News: Just How Reliable are the Boeing 787 Batteries?

For an interesting discussion of reliability when you teach Chapter 17 in our text, we turn to The New York Times (Feb.27, 2013) article on how U.S. and Japanese aviation authorities have confronted a steep learning curve trying to unravel what caused last month’s battery failures on a pair of Boeing 787 Dreamliners. The lithium-ion batteries are commonplace in consumer electronics and electric vehicles, but despite being lighter and more efficient than older technology, they have never been used in aircraft as extensively as on Boeing’s flagship jetliner. After 7 weeks of nearly round-the-clock efforts, the National Transportation Safety Board has failed to find the root cause of the dangerous battery malfunctions that grounded the entire 787 fleet. Industry and government officials on both sides of the Pacific increasingly are skeptical a breakthrough is imminent.

Before approving the Dreamliner to begin carrying passengers in late 2011, regulators embraced Boeing’s risk assessment showing that the chance of a 787 battery meltdown was about one in 10 million flights (That means R= 0.9999999). That is roughly 100 times safer than some of the industry’s most reliable jet engines, which on average malfunction and have to be shut down roughly once every 100,000 flights.

But the U.S. Department of Energy (DOE) sees Boeing’s initial risk analysis as unrealistic, particularly considering variations among parts. “When carefully examining the nature of the material or the tolerance possible within the manufacturing process, it is difficult to arrive at those [risk] numbers,” writes DOE. In commercial use, the batteries have now ruptured and burned twice in less than 50,000 flights (or an R=0.99996). Contrary to FAA projections of an extraordinarily low likelihood of a serious airborne mishap, the Energy Department says the malfunction rate of the batteries has been higher than would be acceptable for uses on the ground. “That wouldn’t be a reasonable number for the auto industry.”

Discussion questions:

1. Why do Boeing’s reliability numbers differ so greatly from observed failures?

2. What are the options for operations managers at Boeing at this point?