Category Archives: Root Cause Analysis – Incident Investigation

Root Cause Analysis - Incident Investigation

Failure of the Teton Dam in 1976

by ThinkReliability Staff

On June 5, 1976, workers were called to the Teton Dam on the Teton River in Idaho to attempt to repair a leak.  Workers in bulldozers narrowly avoided being sucked into the dam with their equipment, and watched helplessly as the dam was breached.  It would kill 14 people and cause nearly hundreds of millions of dollars in property and environmental damage.  To examine what went wrong, we can perform a visual root cause analysis, or Cause Map.

The Cause Mapping process begins by determining the impacts to an organization’s goals.  From the perspective of the government, specifically the Bureau of Reclamation, the safety goal is impacted because of the 14 deaths.  The environmental goal is impacted due to the severe impact the dam failure and subsequent flooding had on the ecosystem of the area.  The customer service goal was impacted due to the evacuation of three towns.  The production goal is impacted due to the abandonment of the dam – at a cost of approximately $50 million.  Additionally, property damage of at least $400 million (some estimates are much higher) is an impact to the property goal.  (There were also substantial claims related to the loss of property and livelihood from impacts to industries, particularly fishing.)

Once we have determined the impacts to the goals, we begin with an impacted goal, such as the safety goal, and ask “Why” questions to determine the cause-and-effect relationships that led to the impacted goals (also known as “problems”.)  In the case of the Teton Dam failure, people were killed due to a massive wave of water released from the dam (which was filled to capacity) when it failed.  The dam failure was also the cause of severe damage to the dam, which was never rebuilt, leading to the impacted production goal.

The failure of the dam was found to be caused by erosion and inadequate strength.  Due to the less than ideal geological conditions of the site (which was picked because there were no “good” sites available), unequal stress distribution and inadequate fill material (which was used from the site) led to reduced strength.  Susceptible materials and seepage from leaks in the embankment, caused by joints that were not resistant to water pressure due to inadequate testing, and inadequate protection from water due to an over-reliance on an ineffective curtain intended to stop flow, led to the erosion.

Many geologists had predicted problems with the dam before it was built.  Specifically, in his book “Normal Accidents”, Charles Perrow states “The Bureau ignored its own data that rocks in the area were full of fissures, and in addition they filled the dam too fast . . . All it takes to bring a dam down is one crack, if that crack wets the soil within the interior portions of the dam, turning it into a quagmire.”

Although tragic, and expensive, the failure of the Teton Dam did lead to many reforms in the Bureau of Reclamation, who is responsible for dam safety.  Detailed geological studies performed in order to determine the causes of the dam failure also provided additional insight to the strength provided by various types of earth, erosion and seepage.

Root Cause Analysis - Incident Investigation

Bridge Collapse In Washington Dumps Cars in River

By Kim Smiley

On May 23, 2013, a section of a four lane bridge over Skagit River near Mount Vernon, Washington unexpectedly collapsed, sending two cars into the river.  No one was killed, but the bridge failure is going to take months and an estimated $15 million to repair.  Additionally, the bridge was one of Washington’s main arteries to Canada with around 70,000 vehicles crossing it a day and detours during the repairs are significantly impacting the region.

So what caused the bridge to fail and how can a similar collapse be prevented in the future? This issue can be analyzed by building a Cause Map, a visual root cause analysis.  A Cause Map intuitively shows the causes that contributed to an issue and the cause-and-effect relationships between them. The collapse occurred after the top of an oversized truck hit a steel girder.  The bridge was a ‘fracture critical’ design, meaning that the design had little redundancy and fracture of one critical component, in this case the overhead steel girder, caused the whole bridge to collapse.  This type of design was common when the bridge was built in the 1950s because it was relatively quick and cheap to build.  Newer designs typically incorporate more redundancy to prevent a single failure from causing significantly damage, but the average bridge in the United States is 42 years old and there are thousands of fracture critical bridges across the nation.

So why did the truck impact the bridge?  This question is more complicated than it might appear on the surface.  The driver appears to have done his due diligence, but he had no warning that his truck was taller than the clearance.  The driver had a permit for hauling an oversized load on this stretch of highway.  The truck was also following a guide who gave no indication of potential clearance issues.  Additionally, there was no sign about low overhead clearance on the bridge because signage wasn’t required.  Signs are only required for overcrossing less than 14 feet and the lowest point on the bridge was higher than that.

The truck was traveling in the outside lane at the time it impacted the bridge.  The clearance over the outside lane of the bridge is lower than the inside lane because of the arch design of the bridge.  The truck’s load was 15 feet 9 inches high and the lowest clearance over the outside lane was 14 feet and 7 inches, but the inside lane has about a 17 feet clearance.  Bottom line, if the truck had simply moved into the inside lane it should have had the clearance to safely cross over the bridge.

This incident is certainly a warning about the need for redundancy in designs, but it also illustrates the need for clear communication.  If the driver had been aware that there was a potential issue, he could have changed lanes (which is a free and relatively easy solution) and the bridge collapse wouldn’t have happened.  Something needs to be changed to ensure that drivers are aware of any potential clearance issues.  In an ideal world, all bridges would be the safest, most up to date designs available, but the reality is that there are thousands of “fracture critical” bridges in use throughout the United States and we’re going to have to find ways to use them as safely as possible for quite some time.

Click here to see a Cause Map of another bridge failure, the 2007 I-35 Bridge Collapse and here to see a Cause Map of the failure of the Tacoma Narrows Bridge.

Root Cause Analysis - Incident Investigation

Update: Cause of Death of Schoolchildren from Tornado in Moore, Oklahoma Not Drowning

by ThinkReliability Staff

Although they are sometimes treated as a static object, Cause Maps (and any root cause analysis) can – and should – change based on updated or corrected information.  A frequent question we get asked is “What if I make a mistake on my Cause Map?”  Well, you fix it.  Let me show you how.

First, a little background on my error.  Last week, I thought it would be important and useful to demonstrate what had happened in the aftermath of Moore, Oklahoma, after a category 5 tornado hit much of the town, including an elementary school.  (See the previous blog.)  Because there are certain expectations for public safety at an elementary school, I decided to focus the analysis on the children who died at the elementary school and the causes that led to their deaths, as well as information on the potential and implemented solutions to reduce that risk.

I researched how specifically the children had died – an unfortunate necessity to ensure that the solutions are working towards the correct causes – and discovered a statement from the Lt. Gov. of Oklahoma the morning after the tornado saying that the children who died had drowned in the basement due to a burst water main.

As you can imagine, sometimes information that is relayed in the immediate scene of a disaster is not entirely accurate.  In this case, the information that the children had drowned was incorrect.  Rather, the children who died were in a classroom and died from blunt force trauma and asphyxiation (suffocation) due to being struck or covered by debris from the tornado.

Once we have verified that our initial cause-and-effect relationship is incorrect, we can correct the Cause Map.  Rather than just erasing the “wrong” causes and adding in the new causes, we suggest crossing off the causes that have been disproved with evidence.  (Click on “Download PDF” above to see an example of a corrected Cause Map.)  This way anyone who may have seen an earlier version of the Cause Map, or heard the same initial erroneous information that was used to make it, will have a clear version of what did happen, including the evidence that verifies the correct information.

Obviously the fact that the children died is tragic, so some may wonder what difference it makes exactly how they died.  Generally people who are killed in tornadoes are killed by objects striking them.   This is why tornado survival drills focus on getting to spots where there is the least possible dangerous debris, or the least risk of the debris becoming dangerous flying objects. Windowless rooms are recommended, because glass can be broken and easily turn into shrapnel.  Basements are recommended because the strong winds associated with tornados have less access to underground areas.  Bathrooms are another option because most everything in a bathroom is secured to the walls and/or floors.  In a pinch, people seek protection under heavy pieces of furniture.  (Survivors from the affected school have said that they hid under their desks and held on for dear life.)

Because the basement is a recommended sheltering location, the possibility of drowning from  equipment that may be damaged by a tornado meant that the basement needed to be reconsidered as a sheltering location.  Because the school did not have a designated safe room, during the 16-minute warning teachers got their students to anywhere they could, including, in many cases, under their own bodies for protection.  (Again, based on the extreme damage to the school the death toll, while tragic, demonstrates the remarkably quick and effective action  taken the teachers.  I can’t emphasize this enough.)  Because this protection was very likely causally related to the death toll (in that without the amazing response from the teachers the death toll may have been much higher), I added additional evidence to the cause of injury.

Be aware that changing the causes may impact the recommended solutions.  The solutions discussed in the previous blog are still valid, especially the recommendations for inclusion of storm shelters for schools in the area.  An additional clarification added in the update is that this has been required since 1999 (after this school was built).  All the schools being rebuilt as a result of the tornado damage will have storm shelters, as will schools built in the future.  Individual communities will still be faced with the choice of which buildings will and will not be required to have storm shelters, and any incentives that will be put into place to encourage their construction.

To view the Outline and Cause Map, please click “Download PDF” above.  Or click here to read more.

Root Cause Analysis - Incident Investigation

Children Killed When School Hit by Category 5 Tornado

by ThinkReliability Staff

A category 5 (the most destructive) tornado hit Moore, Oklahoma on May 20th, destroying the town and killing 24.  Of those killed, 7 were elementary school children, who drowned when water mains burst in the basement where they were sheltered.

Examining this tragedy can help provide lessons to reduce the risk of this issue happening again.  We can analyze the tornado impact at the most severely impacted elementary school in a Cause Map, in order to visually diagram the cause-and-effect relationships that led to the tragic deaths.

First, we determine the impacted goals.  In this case, all other goals are overshadowed by the deaths of seven  elementary students, and injuries to dozens.  In addition, the school was completely devastated (demonstrating the unbelievable destructive power of the tornado), resulting in early school closure and intense rescue, recovery and cleanup.

To perform our root cause analysis, we begin with the safety goal and ask “Why” questions.  The deaths in this case are reportedly due to drowning, which occurred when children in the basement (a recommended sheltering location in the case of tornadoes) drowned due to water from bursting water mains.  The specific failure mechanism of the failure is not known (and may never be due to the extreme levels of damage) but is likely related to the direct strike of the tornado, which is common in the area (close to the center of tornado alley).

Students who were injured by crushing and asphyxia were in the hallways and bathrooms of the school.  (These are recommended sheltering locations for buildings that don’t have basements.)   It is remarkable that, despite the complete annihilation of the school, students who were sheltered in hallways and bathrooms all survived, thanks in many cases to teachers protecting them with their own bodies.  A 16-minute warning from the National Weather Service combined with carefully rehearsed crisis plans that were put into action, allowed the best possible protection for students in a school without a safe room or storm shelter.

This storm has reignited the discussion about expectations for safety shelters in public places that are prone to natural disasters.  The devastating loss at the school has also raised the safety issue of ensuring that the locations used for shelter are cleared of other potential hazards, such as water mains and fire risks.  Because of the relatively short warning time (16 minutes in this case, which is above average) before a tornado strikes, emphasis on tornado drills and safety plans should continue.

To view the Outline and Cause Map, please click “Download PDF” above.  Or click here to read more.

Root Cause Analysis - Incident Investigation

Emergency Plan Could Have Saved Lives in TX Plant Explosion

by ThinkReliability Staff

Investigations are still ongoing to determine details on what caused the April 17, 2013 explosion in West, Texas (the subject of a previous blog).  The death toll has risen to at least 14, including 10 emergency workers.  Around 200 are believed to be injured.  The deaths were caused by the explosion of the site AND the proximity of the victims to the site.  The emergency workers were on-site fighting a fire (which was the ignition source of the explosion), but many of those injured had no real reason to be in such a proximity that they would be injured.   

Warning systems and emergency notifications may have resulted in some of the non-emergency response victims getting out of harm’s way.  However, warning systems and notifications like those required for other industrial sites including oil refineries and chemical plants are not required at fertilizer plants.  The plant owner did not comment on emergency management plans for the site.  Senator Barbara Boxer of California will attempt to determine if those requirements need to be strengthened. 

However, even if a warning system had provided sufficient protection to keep nearby citizens from harm, the property damage would have been extensive.  Many properties – including homes and schools – nearby were severely damaged in the blast.  This has led some to believe that there should be an enforced geographical buffer between these types of industrial facilities and other types of facilities, like homes and schools.  The mayor of West has suggested that the plant be rebuilt away from populated areas. 

More and more concerns are being raised about the safety of the plant itself – and the safeguards that could have prevented this explosion.  Despite the large amount of potentially explosive ammonium nitrate stored at the plant, the plant did not have a sprinkler system or fire barrier (which may have prevented the fire from igniting the fertilizer).   

Industrial plants such as these are regulated by a host of state and federal agencies, including the Environmental Protection Agency (EPA).  The EPA required a worst-case scenario from the West site, which identified a release from an anhydrous ammonia storage tank.  The risk of fire or explosion, and the storage of ammonium nitrate were not identified in the scenario, provided in 2011.  (The facility was fined in 2006 for not filing its risk management plan.) 

A key concern is the amount of fertilizer (270 tons) that was stored at the site – which was not disclosed with local governments or federal agencies.  Ammonium nitrate can be used as an explosive (~2.4 tons were used in the Oklahoma City bombing in 1995).  The high volume of ammonium nitrate was not known or disclosed to local or federal officials.   

Most of the victims in this incident were first responders – who had reported to the fire, not knowing the risk they were taking.  The facility had not disclosed the dangers on site, had not provided adequate protection from fire, and had provided little in the way of an effective emergency response plan.   

Every industrial site should have an up-to-date risk/emergency management plan.  The plan needs to be updated whenever new hazards are brought on-site or identified.  It is crucial that these plans be developed and shared with local response organizations, such as fire-fighters, so that they can be prepared for any potential issues.  These plans should also include community engagement to provide necessary information to people in the area as to what actions should be taken.  Existing incident investigations for industrial incidents can be used as a basis for creating these plans.  But, you don’t need to wait until you have a problem at your facility.  Taking the lessons learned from disasters that have already taken place can save your facility – and your community – a tot of heartbreak.   

Remember: A smart man learns from his mistakes, but a wise man learns from others’ mistakes. 

Root Cause Analysis - Incident Investigation

Contaminated Water Issues Remain at Fukushima

by ThinkReliability Staff

High levels of contaminated water leaving the highly damaged reactors at the Fukushima Daiichi nuclear power plant in Japan are creating issues for the personnel on site, who are working frantically to keep the reactor safe and working towards decommissioning and closing down the site.  Additionally, there is continued concern for the ongoing safety of the site, as the high volume of water could potentially threaten the safety of the reactors.

We can look at these issues in a Cause Map, or visual root cause analysis.  With a Cause Map, the first step is to determine how the issue impacts the organization’s goals.  In this case, we can consider the goals from the perspective of the utility company that owns the power plant.  There is an impact to the safety goal because of the potential risk for another accident, according to the Chairman of the Nuclear Regulatory Authority.  The leakage of contaminated water is an impact to the environmental goal.  There is concern about the lack of a comprehensive plan by the utility, which can be considered an impact to the customer service goal.  The massive construction efforts required to install tanks to store the water are an impact to the property goal and the efforts by the workers to control the flow are an impact to the labor goal.

Once the impacts to the goals have been determined, the next step is asking “Why” questions to determine the cause-and-effect relationships that led to the incident.  In this case, the issues resulting in the high rate of contaminated water needing to be stored are that high rates of water are entering the reactor, becoming contaminated due to the damage inside the buildings from the earthquake and tsunami on March 11, 2011, and the water has to be removed from the building.

The water is entering the buildings because the plant is in the groundwater flow path from the mountains to the ocean and there is insufficient protection to prevent the water accessing the plant.   Severe cracking in the reactor buildings from the earthquake/tsunami are unable to be repaired due to the high residual levels of radioactivity.  The utility rejected plans to build a wall to protect the reactor.  It is believed this is because the utility had planned to dump the water into the ocean.   Additionally, according to the Japan Atomic Energy Commission, the issues from the water weren’t something that were thought of, as the focus was on the nuclear issues.  All involved in the cleanup, including the utility, have had their hands full, so it’s likely something as benign-seeming as water just wasn’t on the list of immediate concerns.

The contaminated water must be pumped out of the building to avoid swamping the cooling systems, which are still needed to remove decay heat that continues to be produced even after the reactors are shut down.  It appears that the original plan was to filter the water and dump it into the ocean, but even after filtering, a high level (about one hundred times the level released from a healthy plant) of tritium would remain.  Public outcry has ended the possibility of being able to dispose of the water that way.  Wastewater pits originally built for this purpose were found last month to be leaking, necessitating the installation of hundreds of tanks for water storage.

For now, the utility workers continue to install tanks to hold the radioactive water.  The task is so overwhelming, it’s not clear if there are any other plans to try and slow the tide of contaminated water.  However, outside experts are attempting to provide assistance.  The International Atomic Energy Agency completed its initial review of the decommissioning plans last month.  The final team report is expected later this month.

To view the Outline and Cause Map, please click “Download PDF” above.  Or click here to read more.

Root Cause Analysis - Incident Investigation

Hundreds of Garment Workers Killed in Building Collapse

By ThinkReliability Staff

Hundreds are confirmed dead – with hundreds more still missing – as a result of a building collapse in Bangladesh.  The number of people who were in the building when it collapsed is unclear, due to spotty records.  Some sources have suggested the death toll may surpass 1,000.

We can examine the causes that led to the deaths in a Cause Map, which visually diagrams the cause-and-effect relationships that led to the tragedy.  First, we capture the impacts to the goals, which includes the extremely significant impact to the safety goal due to the high number of deaths as well as many other goals, including compliance, production and the impact to the labor goal resulting from the rescue and recovery operations.

The deaths were caused by the collapse of a building which was partially occupied at the time. The building housed five garment factories, as well as a bank and other shops.  Even though cracks appeared in the building   and inspectors requested evacuation and closure of the building, garment workers were ordered back to work.    The bank was evacuated, and the shops were already closed.  Despite deplorable conditions (brought to the attention first by a building fire last November and now by this tragic collapse),  workers (mainly young women)   can still be found to work in the garment industry because the average wages in the country are so low.  Eight people, including the building owner and engineers, have been charged as a result of the collapse.

The building, which was illegally built 3 stories too high, was not up to code and not approved by the government.  The building was built on wetland and used substandard materials for construction. As a result of this collapse, the government has said it will form a committee to ensure the safety of buildings and workers.  Shops in the US and Europe that sell garments produced in Bangladesh have distanced themselves from the companies housed in the buildings while many consumers call for more oversight from these companies, who utilize cheap labor in Bangladesh to create their goods.  The garment industry accounts for 77% of Bangladesh’s exports.

It is hoped that this recent tragedy will increase the attention paid to worker safety by the government within Bangladesh as well as consumers who buy the end product abroad.

To view the Outline and Cause Map, please click “Download PDF ” above.

Root Cause Analysis - Incident Investigation

The 8 Worst Typos Ever Made

By ThinkReliability Staff

When we perform a root cause analysis, we occasionally find that something as seemingly minor as a typo has had a huge impact on an organization’s bottom line, their reputation, or even public safety.  The following is a collection of some of the worst typos ever made, with respect to impacts to the organization’s goals.

8. Misspelling your own name 

The Oops: In 2008, a New Hampshire newspaper misspelled its own name, in the front page title, specifically by adding an extra “s”.  Missouri State University misspelled its own name on bags provided to students (Univeristy [sic]).  The error was pointed out by a student.  However, the most well-known of this kind of error probably occurred when “Chile” was misspelled on their 50-peso coin.  The misprinting occurred in 2008, but was not noticed until late 2009.  (Rather than CHILE, the coin said “CHIIE” [sic].  The coins are now collectors’ items.)

The Impact:  The general  manager of the Chilean mint was fired for the coin error.  In the newspaper and university cases, actual cost was minimal and the main impact was abject embarrassment.  However, typos can frequently result in loss of opportunities.  Some recruiters have said that when they get multiple submissions for a single job, resumes with errors go straight to the shredder.

7. Counting on a computer to do your job for you 

The Oops: On January 7, 2009, the US Army admitted that 7,000 letters addressed “Dear John Doe” were sent out to family members of soldiers killed in Iraq.

The Impact: The Army immediately issued a formal apology and sent a personal note to the families.  The letters were sent to the correct families, but there must have been a devastating moment for the families when they thought they may have received someone else’s letter . . . and then realized they hadn’t.

6. Entering the wrong number 

The Oops: On February 5, 2011, an employee at a company in Japan listed 610,000 shares of a job recruiting company at 1 yen apiece.  What it really meant to do was list 1 share at 610,000 yen (~$5,000).  A surprising number of similar stories abound, including a listing on April 5, 2006 for flights from Canada to Cyprus for $39 CAD, instead of $3,900.

The Impact: Although the company in Japan tried to cancel the order, it was processed by the Tokyo Stock Exchange, resulting in a loss of $225 million.   In the case of the surprisingly cheap airline tickets, they were honored by the airline (after initially trying to cancel the tickets) to 500-2000 people, resulting in a very expensive typo indeed.

5. Incorrect punctuation 

The Oops: A communications company in Canada thought it had a five-year deal beginning in spring 2002 with a utility company to add cable lines to thousands of utility poles.  Then the utility company cancelled in early 2006.  The Canadian Radio-television and Telecommunications Commission determined that, because of an extra comma, the contract said that the contract could be cancelled with one-year’s notice, even during the first five years.  (The area in question said the contract: “shall continue in force for a period of five years from the date it is made, and thereafter for successive five year terms, unless and until terminated by one year prior notice in writing  by either party.”)  A missing hyphen in the coded computer instructions was partially responsible for the loss of steering on Mariner 1, which was launched on July 22, 1962.

The Impact: After the cancellation, the utility upped its rates for the use of the poles, which will result in the communications company paying about $2.13 million more than it thought.  But if you think that’s expensive, even worse was the loss of Mariner 1, which had to be blown up when it could no longer be steered.  The value of the Mariner 1 in 1962 was $18.5 million.

4. Using the wrong units 

The Oops: The Mars Climate Orbiter was lost on September 23, 1998 while trying to establish orbit around Mars.  Turns out the trajectory was lower than expected (allowing the orbiter to be subjected to the extreme heat of the Martian atmosphere) because incorrect velocity changes were used in calculations.  Specifically, results from a software program were provided in pound force (English System of Units) and the program predicting the velocity assumed the results were  in Newtons (International System of Units, or SI), a factor of difference of 4.45.  (Read more about the Mars Climate Orbiter.)

The Impact: The Mars Climate Orbiter was destroyed with a complete loss of mission.  The orbiter cost $125 million in 1998.

3. Leaving out a (very important) word 

The Oops:  The interesting thing about some small words (like “not” or “out”) is that they change the meaning of the entire sentence.  A man named Bruce Wayne Morris (who does not become Batman) was sentenced to death in 1987 after the jury was given the choice of death or prison for life with the possibility of parole.  The choice was in fact between execution or a life sentence without parole.

The Impact: Morris’ death sentence was reversed by a federal appeals court in 2001 – that’s right, 11 years later.  (The cost of 11 years worth of deliberation and appeals is not known.)  It is thought that the jury originally opted for the death sentence rather than worrying about him being released on parole at some point in the future.

2. Checking the wrong box 

The Oops:  On January 28, 2013, Evan Spencer Ebel was released from jail, the result of a clerical error.  In 2008, while serving eight years, Ebel pleaded guilty to assaulting a prison guard.  The additional sentence was to be served after the original eight-year sentence.  Instead, the record indicated that the second sentence was to be served concurrent with the original sentence.

The Impact: Ebel is believed to have murdered a pizza delivery man on March 17 and the executive director of the state Department of Corrections on March 19 before he was killed by deputies in Texas on March 21.  A similar situation also ended in tragedy when Charles Anthony Edwards III was mistakenly discharged  in January 2012 from a high-security mental hospital in California, where he is suspected of fatally stabbing a shop owner.

1. Writing illegibly 

The Oops:  While bad penmanship may not necessarily be considered a typo, it can result in the same kinds of problems.  Bad penmanship means that the person who has to read it is much more likely to read it incorrectly.  In one such case, the registration for a ship’s Emergency Position Indicating Radio Beacon (EPIRB) was written sloppily, and a “C” become a “0”.  This didn’t much matter until more than two years later, on March 24, 2009, when the ship (Lady Mary) began to sink and set off its EPIRB.  Because the code was entered incorrectly, it took more than an hour and a half to locate the ship.

The Impact: By the time the Lady Mary was reached (the delay was due to other compounding errors as well), only one crew member was able to be saved.  The other six men were lost at sea.

What to do so this doesn’t happen to you 

When something is important, give it an extra edit.  Specifically, find someone who is not a coworker (a coworker will likely gloss over the same things you did, like the name of your organization).  Motivated teenagers make great editors.  Offer them a dollar for every error they find.  (It’s well worth it.)

Note that legal documents, given the importance of their exact wording and difficulty changing any whoopsies, should be extra, extra carefully edited.

If you really don’t have time to get an independent edit, try reading it out loud.

When your computer is doing some of the work for you, it’s probably a good idea to actually look at a few of the results.

When you’re working with numbers, which are much more difficult to check for errors than words (“univeristy” [sic] is not a word, but 39 is still a number), perform a related math calculation.  One that in particular could have come in handy here is the percentage reduction in the cost of the item.   (Plane tickets at 99% off?  Maybe you want to look at that one again.)

Also, your math teachers weren’t kidding about always using units with your numbers.  Or else you might as well answer the question “How far is it?” with “10”.  If at any point in your analysis a different unit of measurement comes up, go ahead and write both, the way many cookbooks and measuring cups now contain both ounces (English System of Units) and milliliters (Metric System of Units).

All the editing tips above may help, but maybe more important is an understanding of the possible impact of a seemingly innocuous typo.  Yes, they happen to everyone.  But before you let them out of your office, take another look.  If someone thinks you’re wasting your time, show them the two million-dollar examples above.

I’ve made a handy sheet to remind you why you care about editing.  To take a look and print it out for your wall, please click “Download PDF” above.

Root Cause Analysis - Incident Investigation

Deadly Explosion at Texas Fertilizer Plant

By ThinkReliability Staff

An explosion at a fertilizer plant in West, Texas, destroyed much of the town and killed between 5-15 people.   (Search and rescue is still ongoing.)  At least 160 were injured but that number may increase.  The material involved in the explosion was ammonium nitrate, a popular fertilizer.

Capturing the impacts to the goals as a result of an issue is essential to understanding the true effect.  In this case, the fatalities and injuries were severe.  The property damage, which included the plant, as well as the homes of more than 100 families, was also extensive.  An environmental impact resulted from the release of ammonia, which is a respiratory irritant. There was some level of evacuation, which can be considered an impact to the customer service goal, though the high number of injuries has led some to believe the evacuation was not widespread enough.  Additionally, ongoing search and rescue, and firefighting operations are an impact to the labor goal.

These goals were all impacted due to the explosion at the fertilizer plant.  Ammonium nitrate can explode when ignited at very high temperatures.  In this case, a fire provided the high heat.  We can capture these causes in a Cause Map, or a visual form of root cause analysis.  The cause of the fire itself is as yet unknown, though if that is determined we can add it to the Cause Map as well.

What is known is that efforts to prevent explosion were ineffective.  The plant did not believe that an explosion was possible.  Its internal safety review had a worst-case scenario of a ten-minute ammonia release, causing no injuries.  It is fairly rare that ammonia nitrate explodes; only 17 known cases of unintended ammonia nitrate explosions resulting in fatalities have occurred since 1921.  Firefighters were on scene fighting the fire when the explosion occurred, leading to many responder fatalities and injuries.  Oversight at the facility was limited; OSHA has not inspected the facility for at least the last five years.

It is worth exploring why large amounts of ammonium nitrate were present.  Ammonium nitrate is an inexpensive, effective fertilizer.  It is particularly good at delivering nitrogen to food-bearing plants, like fruit trees.  The use of nitrogen greatly increases the yield of food from these plants.  (It is said to increase the carrying capacity, or number of people who can be supported by a hectare of land – from 1.9 to 4.3.)  Given the shortage of food-growing land, this is certainly important.   However, the benefits must be considered alongside the risk and certainly in the future more oversight of these types of facilities may be needed to protect the public from the process as they benefit from the results.

To view the Outline and Cause Map, please click “Download PDF” above.

Root Cause Analysis - Incident Investigation

Seat Belts: A Simple Solution That is Still Underused

By ThinkReliability Staff

One of the most frequent questions we get is “What’s the root cause?”  The problem with that question is that there is never just one, root cause.  Rather, the ‘root cause” should be thought of as a system of causes, much like the roots of most plants are a system.  But the idea of a root cause is attractive – only one thing to find, analyze and solve.  There are a few, rare situations that are almost one, root cause.  One of them is the use of seat belts.

Not wearing a seat belt can cause all kinds of problems, in any kind of vehicle.  In passenger vehicles, seat belts saved more than 75,000 lives from 2004 to 2008, according to the National highway Traffic Safety Administration (NHTSA).  Over that same period, more than 26,000 more lives WOULD have been saved if everyone wore a seat belt.  Unfortunately, not everyone does.  According to the National Safety Council (NSC), seat belt use varies by the type of vehicle but is around 80%.

It’s not just cars that are at issue.  On March 29, 2013, a man was thrown from an experimental plane and killed when the canopy came off.  He wasn’t wearing a seat belt, which would have almost certainly kept him from being ejected – and killed.  Although the FAA requires that safety belts be fastened while crewmembers are at their duty  stations, the pilot, who was killed, had unfastened his safety belt to troubleshoot problems with the battery and apparently did not successfully re-fasten the belt.   (The instructor was not ejected and was able to safely land the plane.)

Although states are trying with mandatory seat belt laws, you can’t force everyone to wear a seat belt all the time.  However, there are many actions being taken to try and increase seat belt use.  As previously mentioned, states are increasing laws and enforcement of requiring seat belt use for all passengers.  Car manufacturers have added warning systems that encourage seat belt use for drivers, and front seat passengers.

Seat belt use (percentage-wise) is lowest among those who have just gotten their license.  As a parent, requiring use of a seat belt every time, every trip, for every passenger can help reduce the risk to your child and his or her passengers.  As an employer, vehicle crashes can have a serious impact to your organization. According to the Occupational Safety and Health Administration (OSHA), motor vehicle accidents are a leading cause of death and injury and cost employers $60 billion annually.  All employers should have a driver safety program.   (Tips on establishing a driver safety program can be found here.)

There is no question that deaths from traffic accidents are a major concern – to everyone.  According to the NHTSA, “seat belts are the most effective traffic safety device for preventing death and injury.”  Because of the effectiveness of seat belts, the  risk of deaths from vehicle accidents, it’s no stretch to say that buckling your seat belt – and getting everyone in your vehicle, family, and organization to do the same – may well be the most important thing you do today.

To view the Outline and Cause Map for the plane ejection, please click “Download PDF” above.  If you’re curious why school buses do not have seat belts, read our previous blog.  Or click here to  read more:

This incident

NHTSA

NSC

FAA

OSHA