Tag Archives: root cause analysis

Root Cause Analysis - Incident Investigation

A Potentially Stinging Situation – Jellyfish Blooms

By Kim Smiley

Jellyfish are some of nature’s most impressive survivors.  They have been around since long before the dinosaurs roamed the earth and continue to thrive.  In some cases, they may even be thriving a little too successfully.  Massive jellyfish blooms can flourish in the right environment and can decimate other species and cause significant damage.

Naturally occurring jellyfish blooms have been around for ages and while they may be inconvenient at times, they aren’t particularly alarming.  The real concern is that manmade conditions may lead to the growth of jellyfish blooms at times or regions that wouldn’t normally see them.  Large numbers of jellyfish can cause a number of serious issues.  Safety is a concern because jellyfish stings are painful and can even be deadly.  Regions that depend on tourism can also be impacted because travelers may avoid areas with large numbers of jellyfish.  Jellyfish have caused damage to ships and buildings when they clog intake lines.  Populations of other species have also been decimated in some areas by jellyfish blooms which can affect commercial fishing operations.

What causes these jellyfish blooms can be explored by building a Cause Map or visual root cause analysis.  A Cause Map intuitively lays out causes that contribute to an issue and shows the cause-and-effect relationships between them.  In this example, the jellyfish blooms grow because jellyfish are well suited for life in low oxygen “dead zones” that are being created in the ocean.

It all starts with fertilizer containing nutrients running into the ocean.  An algae bloom forms as algae feed on the nutrients.  Eventually the nutrients are depleted and the algae dies off leading to the growth of a bacterial bloom as bacteria feed on the dead algae.  The bacterial bloom depletes the oxygen making the region unsuitable for most species.  However, the opportunistic jellyfish can survive and even thrive in low oxygen levels.  Jellyfish are able to rapidly grow and reproduce quickly so the population surges upward in an environment with few predators and little competition.

A few facts so that the reproductive abilities of jellyfish can be fully appreciated: a single female jellyfish can release tens of thousands of eggs per day, and jellyfish are able to double their weight in a single day if food is abundant.

Eating habits of jellyfish also make it very difficult for other species to move back into the region even if oxygen levels increase.  Jellyfish not only compete for the same food as larvae of other species, plankton, they are fond of eating larvae and eggs.  It’s difficult to compete with a species that is both a predator and competitor.

Before anyone has nightmares of huge jellyfish causing wide scale destruction, I should note that researchers have not found evidence that jellyfish are in danger of overrunning the oceans.  But many scientists do believe that human activities have contributed to jellyfish blooms growing in localized areas.  It’s always worth trying to understand how human activities are impacting our environment, especially when a species so well equipped for survival is involved.

To view a high level Cause Map of this issue, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

50 Presumed Dead in Canadian Train Disaster

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By ThinkReliability Staff

A tragic accident devastated the Canadian town of Lac-Mégantic, Quebec on July 6, 2013.  Much about the issue is still unknown.  When investigating an incident such as this, it can be helpful to identify what is known and information that still needs to be determined.

What is known: a 73-car train was parked in Nantes, Quebec, uphill from Lac-Mégantic.  Of the cars, 72 contained crude oil.  The train was left unattended and late the evening of July 5, 2013, a fire broke out in the locomotive.  While the fire department of Nantes was putting out the fire, they turned off the train’s main engine.  Less than two hours later, the train rolled down the track and derailed in Lac-Mégantic.  After subsequent explosions and long-burning fires, 24 people have been confirmed dead.  26 more are missing.   Much of the town and the train – and the evidence in it – is destroyed.

What is not known: The cause of the initial fire on the train is not known.  Whether or not the fire department should have explicitly notified the train engineer that the main engine had been shut off is not known.  What happened that allowed the train to roll downhill is unknown.

With this number of unknowns, it is helpful to visually lay out the cause-and-effect relationships that occurred, and what impact they had on those affected.  This can allow us to see the holes in our analysis and identify where more evidence is needed.  Once as much evidence as possible has been obtained, additional detail can be added to the cause-and-effect relationships.  Ensuring that all causes related to the incident are included will provide the largest number of solutions, allowing us to choose the most effective.  We can do all this in a Cause Map, or visual root cause analysis.

The first step in using any problem solving methodology is to determine the impact caused by the incident.  In this case, the deaths (and assumed deaths) are our most significant impact.  Also addressed should be the crude oil leakage (though much of it was likely burned off), the high potential for lawsuits, the possible impact on rail shipments, the destruction of the town and the train, and the response and cleanup efforts.  These form the initial “effects” for our cause-and-effect analysis.

Asking “Why” questions allows us to further develop the cause-and-effect relationships.  We know that for the train to roll backwards down the hill, both sets of brakes had to be ineffective.  The railway company has stated that the air brakes released because the main engine had been shutdown.  However, according to the New York Times, “since the 19th century, railways in North America have used an air-braking system that applies, rather than releases, freight car brakes as a safety measure when it loses pressure.”  This certainly makes more sense than having brakes be dependent on engine power.

The hand brakes functioned as backup brakes.  The number of cars (which, when on a hill, affects the force pulling on the train) determines the number of handbrakes required.  In this case, the engineer claims to have set 11 handbrakes, but the rail company has now stated that they no longer believe this.  No other information – or evidence that could help demonstrate what happened to either sets of brakes – has been released.

Also of concern are the style of train cars – believed to be the same that the NTSB identified in a report on a previous train accident as “subject to damage and catastrophic loss of hazardous materials”.

In a tragedy such as this one, the first priority is to save and preserve human lives in every way possible.  However, once that mission is complete, evidence-gathering to determine what happened is the next priority.  As evidence becomes available it is added directly to the Cause Map, below the cause it supports or refutes.  Additional causes are added as necessary with the goal of determining all the cause-and-effect relationships to provide the largest supply of possible solutions to choose from.

The company involved has already stated it will no longer leave trains unattended.  That should be a big help but, given the consequences of this event, other solutions should be considered as well.

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

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

Root Cause Analysis - Incident Investigation

8 Marines Killed During Training Exercise With Live Ammunition

By ThinkReliability Staff

Eight Marines were killed, and seven Marines and sailors were injured, as the result of the unexpected explosion of a 60 mm round inside a mortar tube during a live ammunition training exercise.  While details are still to be determined, it is known that the unexpected explosion of a mortar round led to the deaths and injuries of those participating in a training exercise with a 60 mm round inside a mortar tube.

Though details of the incident are still unknown, we can begin a Cause Map, or visual root cause analysis, diagramming possible causes which remain to be investigated.  As more information becomes available, evidence supporting or excluding potential causes is included on the Cause Map.

We capture the What, When and Where of the incident in the Problem Outline.  In this case, a training accident/ explosion occurred on March 18, 2013 at about 10:00 pm at the Hawthorne Army Depot in western Nevada.  At the time, a mountain training exercise with live ammunition was using a 60 mm round inside a mortar tube.  A traffic accident that may be related has been mentioned in the news, but no detail has been provided.  To ensure that this line of inquiry is followed during the investigation, we can include it in the “different, unusual, unique” line of the problem outline.

Data that is known, such as the types of damage resulting in deaths and injuries, is included with supporting evidence, in this case testimony of the hospital spokesman.  Causes still to be determined, such as whether the mortar round exploded prematurely in the tube, detonated after being fired, or whether more than a single round exploded are included with question marks and joined by “OR”.  When evidence is obtained throughout the investigation related to a given cause, it is included directly beneath the cause it controls.  Along with the unknown method of detonation of the round, it is unknown whether an issue with the firing procedure, a malfunctioning firing device, or a malfunction in the explosive mortar is to blame.

More details should be coming soon since the use of 60 mm mortars is suspended until the review of this incident determines what happened.  At that time, those causes ruled out by evidence can be crossed off (but left on the Cause Map so that others know they were considered and ruled out as more evidence became available).

At that time, solutions that best address the issues that were causally related can be brainstormed, evaluated, and implemented.

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

Root Cause Analysis - Incident Investigation

Plan to Control Invasive Snakes with Drop of Dead Mice

By Kim Smiley

Brown tree snakes are an invasive species that was inadvertently introduced to Guam where they have decimated native bird populations and done massive environmental damage.  It’s estimated that there are about two million of these snakes  on the island.  The newest plan of attack in the battle to control the brown tree snake population is to poison the snakes by parachuting dead mice laced with pain killers onto Guam.

The problem of invasive brown tree snakes can be analyzed by building a Cause Map, a visual root cause analysis.  A Cause Map is built by asking “why” questions and adding the causes to intuitively show the cause-and-effect-relationships.  The first step is to identify the goals that are impacted.  In this example, the environmental goal is impacted because the balance of native species on Guam has been altered.  This has happened because the native bird population has been decimated because they have been eaten by an invasive predator, the brown tree snake.  The spider population has also exploded because many of the birds, their main predator, have disappeared.  The snakes also cause significant and expensive power outages on Guam as they climb into electrical equipment.

Brown tree snakes have taken over Guam for several reasons.  First, the snake was accidently introduced to the island, likely as a stowaway in military cargo after World War II.  Once the snake was on the island, it thrived because the species had no major predator on the island, there was little competition for resources, and there was an abundant food source.  There was little competition because Guam had only one other snake species prior to the introduction of the brown tree snake.  The native snake species is blind and significantly smaller, preying mostly on insects.  The brown tree snake had ample food because it is a pretty flexible predator happy to eat birds, lizards, bats and small mammals.  In fact, the brown tree snake has found Guam so hospitable that the snakes grow larger on Guam than in their native habitat where predators are more plentiful and food is more limited.

Presence of these snakes on Guam has caused massive damage.  Nine of twelve native bird species are extinct on the island.  The snakes have also eaten a significantly amount of the small mammal population.  There has also been a huge impact on vegetation on Guam since the snakes have wiped out many of the pollinators.  Scientists have been trying to find ways to improve the situation.

The newest plan involves dropping dead mice laced with pain killers onto Guam.  The pain killers are deadly to the snakes if ingested.  The mice will be attached to something called a flagger, which is two pieces of cardboard attached with a streamer.  The flagger should act like a parachute and catch in the tree canopy, which is where the snakes predominately spend their time.  The hope is that the snakes will then eat the pain killer laced mice, thus reducing their population.  The current plan is to drop about 2,000 mice over an enclosed area to determine if this is an effective method of brown tree snake population control.  If it works, more dead mice could be headed Guam’s way in the future.

To view a Cause Map of the brown tree snake problem and a Process Map of the plan to drop dead mice, click on “Download PDF” above.  To view a similar example about controlling feral cats on Macquarie Island, click here.

 

 

 

Root Cause Analysis - Incident Investigation

Engine Room Fire Results in Cruise Ship Nightmare

By Kim Smiley

On February 10, 2013, an engine room fire on the Carnival Triumph cruise ship knocked out a significant portion of the ship’s electricity and crippled the propulsion system.  Passenger descriptions of the rest of their “vacation” have included the words hellish and nightmare.

This incident can be reviewed by building a Cause Map, a visual format for preparing a root cause analysis.  A Cause Map intuitively lays out the causes that contributed to an issue to visually show cause-and-effect relationships.  The first step in building a Cause Map is to fill in an Outline which includes the basic background information for an issue as well as the ways that the problem impacts the goals.  In this example, a number of goals are impacted such as the customer service because of the many unhappy passengers and negative media coverage; the schedule goal because the delay of the return of the ship; and the safety goal because of there was a potential for illness.    Once the impacts to the goals are determined, the Cause Map is built by asking “why” questions.

Starting with the safety goal, the first step would be to ask “why” there was a potential for illness.  Illness was a very real possibility because of the unsanitary conditions that existed onboard the ship.  The toilets in the aft portion of the ship couldn’t be flushed because the sewage system was inoperable after the fire.  Full toilets and the rolling motion of the ship made a disgusting and unhealthy combination.  There have been many reports of human waste on floors and even leaking between levels onboard the ship which is probably not anybody’s idea of an ideal vacation setting.  Add in the limited electricity available after the fire and passengers faced filthy cabins without lighting or air conditioning.  Food also became an issue because the limited electricity made preparation of hot meals difficult and the supplies diminishing as the ship remained at sea longer than planned.  The ship’s return was delayed because it had to be towed back to port after the fire wiped out its propulsion.

Investigators are working to determine what caused the fire that started this mess.  They have determined that a leak in a fuel oil return line was part of the problem, but it may be months before the details are known.

What is known is that cruise ship fires aren’t as rare as might be expected.  There were reports of 79 fires onboard cruise ships from 1990 to 2011.   While more information is needed to understand the details of this particular fire, there has been speculation that lack of adequate preventative maintenance may contribute to this issue across the cruise industry.  Keeping a cruise ship in port for a week’s worth of maintenance costs tens of millions of dollars and companies have to try to balance this cost with the risk of an issue during operation.  And the risk is big.  If something goes wrong during operation, like it did in this example,  it can be very expensive.   The total cost of the fire onboard Carnival Triumph is estimated to be $80 billion, including 12 cruises that have already been canceled to allow time for repairs.  In addition the negative press isn’t exactly helping entice potential customers into booking a cruise.  Balancing the cost of maintenance with the risk of not performing it is an issue that many industries face.  No one wants to spend money on unnecessary maintenance, but no company wants to make headlines that have the word nightmare in them either.

To view a high level Cause Map of this issue, click on “Download PDF” above.

Check out our previous blog about  the Costa Allegra , another cruise ship that lost power.