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

OM in the News: The Two‑Cent Failure That Shut Down a Factory

In operations management, small and overlooked details can have outsized consequences. A well‑known example comes from a manufacturing plant where a single 2‑cent bolt caused nearly a month of downtime. The incident illustrates that the failures that matter most are not always the ones that occur most frequently, writes Industry Week (Sept. 22, 2026).

Predictive maintenance systems (see Ch. 17 in your Heizer/Render/Munson text) are designed to monitor components that commonly wear out. Sensors track performance, data models identify warning signs, and technicians intervene before breakdowns occur. When focused on familiar failure patterns, these systems perform effectively and prevent costly interruptions.

However, predictive systems only detect what they are built to observe. In this case, the bolt that failed was not instrumented. It was considered too inexpensive, too simple, and too unlikely to break. Because it was not monitored, the system had no way to provide an early warning. When the bolt snapped, the machine stopped immediately.

The true cost of the failure was not the price of the bolt but the time required to recover. The part was specialized and not kept in inventory. It had to be ordered from a specific supplier, and until it arrived, the production line remained offline. The result was weeks of lost output—far more expensive than any of the common failures the system was designed to predict.

The OM lesson is clear: rare failures can be more damaging than frequent ones if the organization is unprepared to respond quickly. Effective maintenance planning requires looking beyond the usual wear‑and‑tear components and identifying parts that, if they failed unexpectedly, would be difficult or slow to replace.

The most costly outage often comes from the part no one thought to monitor. Recognizing this blind spot—and planning for it—is essential for building resilient operations.

Classroom Discussion Questions

How should organizations balance monitoring common failures with preparing for rare but high‑impact failures?
What criteria—not just failure frequency—should be used to decide which machine components deserve monitoring or backup inventory?

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: Why Los Angeles Should Read Chapter 17

A recent water main rupture in Los Angeles

We know that not every OM instructor covers Chapter 17, Maintenance and Reliability. It is after all, the last chapter in a long text. But if Jay has told me once, he has lectured me a 1,000 times: “Maintenance is one of the most critical of the 10 OM decisions that managers make!” And so it appears that the city of Los Angeles should have been reading Chapter 17 for the past 3 decades.

As The New York Times (Sept. 2, 2014) reports: “The scene was apocalyptic: a torrent of water from a ruptured pipe valve bursting through Sunset Boulevard, hurling chunks of asphalt 40 feet into the air as it closed down the celebrated thoroughfare and inundated the campus of UCLA. By the time emergency crews patched the pipe, 20 million gallons of water had cascaded across the college grounds.”

It was just the latest sign of a continuing breakdown of the public works skeleton of the U.S.’s 2nd-largest city: its roads, sidewalks and water system. With each day, another accident illustrates the cost of deferred maintenance on public works, with an estimated $8.1 billion it would take to do the necessary repairs. The city’s annual budget is $26 million. LA’s problems reflect the challenges many American cities face after years of recession-era belt-tightening prompted them to delay basic maintenance. “It’s part of a pattern of failing to provide for the future,” said one UCLA prof.

The average LA car owner spends $832 a year for repairs related to the bad roads, the highest in the nation. Families here routinely spring for expensive strollers to handle treacherous sidewalks. Close to 40% of the region’s 6,500 miles of roads and highways are graded D or F. More than 4,000 of the 10,750 miles of sidewalks are in severe disrepair. More than 10% of the 7,200 miles of water pipes were built 90 years ago. At the current level of funding, it would take the city 315 years to replace them.

Classroom discussion questions:

1. Why is maintenance such an important part of OM?

2. What strategy might LA take at this point?