Monthly Archives: November 2012

Root Cause Analysis - Incident Investigation

Gas Explosion Rocks Springfield, Massachusetts

By Kim Smiley

On Friday, November 23, 2012, a massive gas explosion rocked downtown Springfield, Massachusetts.  No one was killed because the area had been evacuated while a suspected gas leak was investigated, but 20 people were injured and many buildings were damaged.

This incident can be analyzed by building a Cause Map, an intuitive, visual way to perform a root cause analysis.  The first step when creating a Cause Map is to document the basic information in an Outline and determine how the goals were impacted.  In this example, the safety goal was impacted because there were injuries as well as the possibility for fatalities.  The material goal was impacted because 42 buildings were damaged, including three that were immediately condemned.  The schedule goal is also impacted because many businesses in the area closed during the necessary inspections and repairs.

Once the impacts to the goals are determined, the Cause Map is built by asking “why” questions.   In this incident, buildings were damaged because there was a major gas explosion.  This occurred because there was oxygen, a spark and a natural gas leak.  Investigators have not been able to determine the source of the spark and may not be able to answer that question due to the extent of the damage.  The gas company has released information on what caused the gas leak.

Someone had called in to report a gas smell in the area and the gas company had sent workers out to investigate and evacuated the area at some point during the process.   The explosion occurred because a high pressure gas pipeline was inadvertently punctured by a worker who was investigating the reported gas smell.  He was using a long metal tool to probe the ground looking for gas underground when the tool accidently hit the pipeline, creating a gas leak.  This occurred because the worker wasn’t aware of the location of the pipeline.  He was using markings on the sidewalk that indicated the location of the pipeline, but the markings didn’t show the correct location.   He moved to what he thought was a safe distant from the location of the pipeline, inserted the tool into the ground and struck the incorrectly marked pipeline.  The gas company has stated that the worker was following standard procedure.

It’s also worth noting that none of the injuries were life threatening.  If the area hadn’t been evacuated at the time of the explosion there would likely have been many fatalities.  At least one local business that would have been opened at the time of the explosion was completely leveled.

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

Root Cause Analysis - Incident Investigation

Does Turkey Really Make you Sleepy?

By Kim Smiley

Every year around this time, Americans start thinking about turkey and that sleepy feeling that hits after a Thanksgiving feast.  It has been common to blame the bird for the post feast drowsiness, but is the idea that turkey causes sleepiness true?

This issue, just like any big engineering problem, can be analyzed by building a Cause Map.  A Cause Map is an intuitive, visual format for performing a root cause analysis.  To build a Cause Map, “why” questions are asked to understand the cause-and-effect relationships between the different causes that contribute to an issue.  One cause in this example is the  fact that turkey is typically eaten at a tradition American Thanksgiving feast.  The rumor that it causes sleepiness likely came from the fact that turkey contains tryptophan, an essential amino acid that is found in protein.  Tryptophan is a natural sedative because it used to help the body produce the B-vitamin niacin, which in turn is used to make serotonin.  The body then uses serotonin to make melatonin which helps regulate sleep cycles.  Higher melatonin levels can make a person feel sleepier.

If you stopped the investigation at this point, it might look like turkey is in fact responsible for that post-Thanksgiving nap, but there is more to the story.  The first important thing to note is that turkey doesn’t really contain that much tryptophan compared to other foods.  Turkey actually has less than chicken, which Americans regularly consume without the need for a nap.  Tryptophan is also much more potent when eaten on an empty stomach, which is probably not the case on Thanksgiving Day.

The conclusion is that you can’t blame the bird.  It’s a myth that turkey causes more sleepiness than other foods.  If you feel sleepy after feasting for Thanksgiving it probably has more to do with the work to prepare the meal and amount of food consumed than the properties of the turkey.  But please don’t let this conclusion ruin your fun; feel free to nap the afternoon away anyway.

Happy Thanksgiving from ThinkReliability.  We hope you have many things to be thankful for this year.

Root Cause Analysis - Incident Investigation

Voting Issues in the 2012 Election

By Kim Smiley

Prior to the election on November 6, 2012, some reporters were predicting that the results of the presidential election, which was expected to be nail biter, may not be known for weeks . While this was obviously not the case, there were a few real  hiccups in the voting process.

The voting issues of the 2012 election can be analyzed by building a Cause Map, an intuitive, visual format for performing a root cause analysis.  The first step of the Cause Mapping process is to create an Outline that lays out the basic information of an issue and also lists the impact to the overall organizational goals.  In this example, the general public is considered the “customer” and the voting issues were an impact to the customer service goal since anything that makes it difficult for eligible voters to cast a ballot means the government is not providing adequate customer service to the public.

The next step is to ask “why” questions to understand the different causes that contributed to the problem.  Why were there issues voting?  Part of what made this specific election difficult was the aftermath of Hurricane Sandy.  Areas in the northeast were still without power.  Temporary polling locations had to be established and the change in the normal process was confusing to voters.  Just providing information to voters was complicated because many homes were still without power or damaged and some residents were displaced.

There was also confusion over changes to voter laws prior to the election.  The most publicized example of this is the voter identification laws passed in Pennsylvania.  A law was passed in Pennsylvania that required all voters to show an official form of photo identification, but the law was challenged in court.  Advocates of the law say that it will prevent voter fraud.  Opponents of the law say that it will prevent eligible voters from being able to cast ballots because not all voters have photo identification, a particular issue for the elderly, poor and minorities.  A judge ruled that the law would not apply to the election because voters didn’t have enough time to acquire their photo identification.  This new law and subsequent ruling confused some poll workers and there have been cases reported where voters were turned away for not having identification when it was not yet required.

There were also very long lines reported at some polling locations.  Some voters in Virginia and Texas waited four hours to vote.  This was caused in part because this was a presidential election and predicted to be very close so there was higher than normal voter turnout.  Long lines tend to happen near the end of the day after the traditional workday ends.  Some polling locations also had problems that slowed the process like broken voting machines or staff that didn’t show up.

Luckily, the voting issues didn’t delay the election results and any voters that were mistakenly turned away because of new laws or unable to vote because of the impacts of Sandy would not have changed the overall result of the election.  But officials could certainly use the lessons learned from the 2012 election to help ensure a smoother process for the next presidential election.

Root Cause Analysis - Incident Investigation

Deadly Superstorm Slams the US

By Kim Smiley

Hurricane Sandy pummeled the Mid-Atlantic region of the United States on October 29th  and 30th, 2012, leaving more than eight million people without electricity, causing massive flooding and killing over 110 people.  The damage done by this storm was massive and economic impacts have been predicted to be as high as 50 billion dollars.

Why was Sandy so devastating?  This question can be answered by building a Cause Map, an intuitive format for performing a root cause analysis.  A Cause Map is a useful tool for breaking down this complicated issue and can help explain why this storm was unique.

In this example, there are a number of things that combined to made Sandy a unique and especially dangerous storm.  First off, Sandy wasn’t just a normal hurricane.  As hurricane Sandy moved to the north it converged with other weather systems turning into a hybrid storm.  This hybrid storm brought with it a combination of extreme summer weather (strong winds with heavy rains) and winter weather (cold temperatures and snow).  Unusual timing of the different weather systems helped this superstorm form.  Hurricane Sandy hit very late in hurricane system and cold air sweeping down from Canada was colder than typical for this time of year, a combination that proved deadly.  The nature of these converging weather patterns also made Sandy a very slow moving storm so that areas experienced higher rain fall and more damage than they might have with a faster moving system.

Normal hurricanes are powered by the warm, moist tropical air and weaken as they travel north.  They also typically turn to the right and head out to sea.  When Sandy converged with the other systems it became an extra-tropical cyclone and actually strengthened as it hit shore.  The effects of these other weather systems also turned the storm left onto land and it took an unusual path over some of the most heavily populated areas of the US, including NYC,  intensifying the impact of the storm.

The timing of Sandy also impacted the peak flood levels.  Sandy hit during a full moon when tides are at the highest point of the month.  During a full moon, the effects of the moon’s gravity are felt the strongest so tides are higher.  The high winds created by Sandy combined with the full moon resulted in a massive storm surge.

Sandy truly was a Superstorm.  Weather systems that normally don’t exist at the same time converged to create a massive storm that moved in a usual path over one of the most heavily populated regions in the US.  And the storm hit at the worst time of the month for flooding.

For more information click here or here.  To view a high level Cause Map of this issue, click “Download PDF” above.

 

Root Cause Analysis - Incident Investigation

The Comet That Couldn’t Fly

By ThinkReliability Staff

“… the most exhaustively tested airplane in history.”

-Expert opinion on the DeHavilland Comet

Today, commercial jet air travel is standard fare. Estimates for the amount of air traffic over the United States in a given day have been in the range of 87,000 flights. With clever planning, clear skies and smooth service, a citizen almost anywhere in the world can get anywhere else by plane in less than 24 hours. But looking back at the history of aviation show us how far safety has come. Consider the DeHavilland Comet, the first commercial jet to reach production. British aviation specialists finalized the Comet’s design with much excitement in 1945 in hopes it would position their industry to establish a revolutionary service in commercial jet flight. Unfortunately, the Comet crashed on January 10th and April 8th in 1954.

What happened? We can identify some of the causes in a Cause Map, or visual root cause analysis.

CAUSE #1: POOR TESTING When you test an extremely heavy object carrying hundreds of people at high speeds thousands of feet above the ground, you would think planning for the worst case scenario would make the most sense. Unfortunately, the Comet tests were performed in tainted conditions on the strongest part of the plane.

Add in the fact that there was no prototype for the plane and you’ve got a test not worth having… and a plane not worth flying.

CAUSE #2: UNEXPECTED PRESSURE Altitude leads to pressure, and pressure puts stress on planes. But this stress wasn’t evenly distributed, and certain parts of the planes’ bodies were unevenly affected. So rather than the expected amount of pressure on the planes, the Comets faced an unforeseen squeeze.  

CAUSE #3: FLYING ABOVE AND BEYOND The Comet flew at twice the speed, height and cabin pressure of any previous aircraft, displaying a rather dangerous amount of ambition.

Combine all of this, Cause Map it, and you’ve got a plane flying under incredible conditions it couldn’t withstand, facing high pressure where it was most vulnerable.

In other words, an airborne recipe for disaster.

FALLOUT #1) SAFETY As expected, the pressure cycle in the planes’ cabins cracked the bodies of the planes. When the planes broke up, the lives of 56 passengers and crew members were lost.

#2) CUSTOMER SERVICE Some British industry institutions have a highly prestigious reputation (the Royal Navy’s impact on British sea travel comes to mind). The loss of the aircraft, though, was a black eye on British Aviation. Aviation historian George Bibel called the Comet an “adventurous step forward and a supreme tragedy.”

#3) MATERIALS/LABOR Effective airplanes have never been cheap, and this was no different. Not only would it cost money to investigate the cause of the accidents, but to replace the airplanes.   

FUTURE SOLUTION The Comet’s tragic crash had one silver lining: the post-crash analysis performed by its designers (including Sir Geoffrey de Havilland) set the precedent for future air accident investigations. In fact, the Comet was redesigned to solve the issues that caused the crashes and would later fly successfully. But by then, Boeing had already taken over most of the commercial jet market.

In the end, the Comet was first in flight but last in the market.

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Want us to cause map a specific plane crash for you? Tell us in the comments and we’ll pilot our way through it.