Monthly Archives: September 2014

Root Cause Analysis - Incident Investigation

Can Airline Seats Get Even Smaller?

By Kim Smiley

Was the experience the last time you flew wonderful?  Did you enjoy all the luxurious amenities like ample elbow room, stretching out your legs, and turning around in the bathroom?  Me neither.  Comfort certainly hasn’t been the top priority as airlines have shrunk seats to cram more passengers onboard, but a new patent application by Airbus really takes things to a whole new level.

They say that a picture is worth a thousand words and I think that is particularly true in this case.  This is a diagram of a patent application for a proposed seat design –

 

I’m not sure about the rest of you, but my backside is sore just thinking about an airplane seat that bears such a strong resemble to a bicycle.

I attempted to build a Cause Map, a visual root cause analysis, in order to better understand how such a design could be proposed because I frankly find it mind-boggling.  The basic idea is that airlines would like to maximize profits and that putting more people on each flight allows more tickets to be sold resulting in more money made.  The average airline seat width has already decreased to about 17 inches from the 18 inches typical for a long-haul airplane seat in the 1970s and 1980s.  Compounding the impact on passengers is the fact that the average passenger has increased during that same time frame.  In general larger bodies are being put in smaller seats, not a recipe for a comfort.

I’m still having a hard time understanding how the correct answer to increasing airline profits is making seats even smaller.  I have to believe that passengers will balk at some point.  At some level of discomfort, a cheap ticket just won’t be cheap enough for me to be willing to endure a truly awful flight.  Even with electronic distractions and snacks, there has to be a point where people would just say no.

There also has to be a number of safety concerns that arise when the size of airplane seats is dramatically decreased.  Survivability in a crash is greatly influenced by seat design because airplane seats are designed to absorb energy and provide head injury protection during an accident.

Just to be clear, there is no plan to actually use this seat design anytime in the near future.  This is just a patent application.  As Airbus spokeswoman, Mary Anne Greczyn said, “Many, if not most, of these concepts will never be developed, but in case the future of commercial aviation makes one of our patents relevant, our work is protected. Right now these patent filings are simply conceptual.” But somebody somewhere still thought this was a good enough idea that it should be patented…just in case.

Root Cause Analysis - Incident Investigation

Children Served Bleach from Reused Milk Jug

By ThinkReliability Staff

For morning snack on September 11, 2014, a substitute teacher’s aide was getting ready to pour water for snack on her first day on the job. Unfortunately, what she poured from a reused plastic milk container was actually a beach solution used for cleaning. The mistake was realized quickly, but not before 28 children and 2 adults ingested some of the bleach. Luckily the concentration was low enough that there were no injuries, although all who ingested the solution were seen at a local hospital.

The substitute teacher’s aide was fired and the school reopened the next day, though the New Jersey Department of Children and Families will be investigating. Clearly serving cleaning solution to children under your care is undesirable. However, firing the person most directly involved without fixing any of the issues that contributed to the mistake may leave an unacceptable risk for the issue to happen again. Although this appeared to be the first time anything like this happened on such a scale in a day care facility, the misuse of cleaning fluid due to confusing containers has happened before. Just this July a woman was given an epidural of cleaning fluid after containers were accidentally switched. (See our blog to learn more.)

Identifying the impacted goals and all the causes that led to those impacted goals allows for more solutions than just firing the person found to be most immediately responsible. The use of a Cause Map, a visual form of root cause analysis, diagrams all the cause-and-effect relationships in order to develop as many solutions as possible so the most effective among them can be implemented.

First the impacts to the goals are identified. The safety goal is impacted because of the potential for injury to the 28 children and 2 adults who drank the bleach solution. The bleach solution was stored in a food container, which can be considered an impact to the environmental goal. The customer service goal is impacted because the children and adults were served bleach solution. The day care worker being fired, and the ongoing investigation by the licensing agency, can both be considered impacts to the regulatory goal. Additionally, the treatment of all 30 who ingested the solution impacts the labor goal.

Beginning with one impacted goal, we ask “why” questions to determine cause-and-effect relationships. In this case, the safety goal impact of potential injury is due to the children and teachers drinking the bleach solution they were served. The bleach solution was served by the fired employee who was apparently unaware that the milk jug actually stored bleach solution. The executive director indicated that the jug was labeled, so this is apparently not an uncommon practice at the site. The question this raises is, why was an old milk jug used to store cleaning solution?

The American Association of Poison Control Centers (AAPCC) says: “DO NOT use food containers such as cups or bottles to store household and chemical products” and “Store food and household chemical products in separate areas. Mistaking one for the other could cause a serious poisoning.” Although the reused container was apparently labeled (though not clearly enough to avoid the mistake), it should never have been reused in the first place. As indicated by the AAPCC, reusing containers between food and cleaning supplies is just too big of a risk. It’s also worth noting that reusing a bottle that contained household chemicals for a different household chemical is another no-no: “Never mix household chemical products together. Mixing chemicals could cause a poisonous gas.” Don’t run the risk at your workplace or home. Don’t reuse food containers for cleaning products or mix cleaning products.   Fortunately the children at this day care center got off without lasting damage in this case.

Root Cause Analysis - Incident Investigation

App Takes Down National Weather Service Website

By Kim Smiley

The National Weather Service (NWS) website was down for hours on August 25, 2014.  Emergency weather alerts such as tornado warnings were still disseminated through other channels, but this issue raises questions about the robustness of a vital website.

This issue can be analyzed by building a Cause Map, a visual format for performing a root cause analysis.  Cause Maps are built by laying out all the causes that contributed to a problem to show the cause-and-effect relationships.  The idea is to identify all the causes (plural), not just THE one root cause.

This example is a good illustration of the potential danger of focusing on a single root cause.  The NWS website outage was caused by an abusive Android app that bogged the site down with excessive traffic.  The app was designed to provide current weather information and it pulled data directly from the forecast.weather.gov website.  The app inadvertently queried the website thousands of times a second because of a programming error and the website was essentially overwhelmed.  It was similar to the denial of service attacks that have been directed at websites such as Bank of America and Citigroup, but the spike in traffic in this case wasn’t deliberate.

It may be tempting to say that the app was the root cause. Or you could be more specific and say the programming error was the root cause.  But labeling either of these “the root cause” would imply that you solved the problem once you fix the software error. The root cause is gone, no more problem…right?  In order to address the issue, NWS installed a filter to block the excessive queries and worked with app developer to ensure the error was fixed, but there are other factors that must be considered to effectively reduce the risk of a similar problem recurring.

One of the things that must be considered in this example is why a filter that blocked denial of service attacks wasn’t already in place.  Flooding a website with excessive traffic is a well-known strategy of hackers.  If an app could accidently take the site down for hours, it is worrisome to consider what somebody with malicious intent could do.  The NWS is responsible for disseminating important safety information to the public and needs a reasonably robust website.  In order to reduce the impact of a similar issue in the future, the NWS needs to evaluate the protections they have in place for their website and see if any other safeguards should be implemented beyond the filter that addressed this specific issue.

If the investigation was focused too narrowly on a single root cause, the entire discussion of cyber security could be missed.  Building a Cause Map of many causes ensures that a wider variety of solutions are considered and that can lead to more effective risk prevention.

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

Root Cause Analysis - Incident Investigation

Explosion Causes Fatality During Hot Work at Fish Processing Plant

By Holly Maher

On July 28, 2014, one contract worker was killed and another seriously injured when an explosion occurred within a fish oil storage tank, blowing the lid off the 30 foot high vessel.  Contractors were on top of the tank, performing required welding on the tank.  The storage tank contained approximately 8 inches of “stickwater” or a slurry of water and fish matter thought to be non-hazardous.

Although the official investigation of this incident continues with participation from both OSHA (Occupational Safety and Health Administration) and the CSB (Chemical Safety Board), we can use a Cause Map to visually lay out the cause and effect relationships known at this point.  As information becomes available, additional causes can easily be added to the Cause Map.

The first step in the Cause Mapping process is to identify the problem by filling out the Outline.  We clarify the date, time, location, and sometimes “what was different about this incident”, which at this point is unknown.  The explosion occurred at ~9:30 on the morning of July 28th, 2014 at a fish processing plant in Moss Point, Mississippi.  The task being performed when the incident happened was welding on the storage tank.  At the bottom of the outline we identify the impact to the goals for the organization, because although you may get many answers to “what is the problem”, the impact to the goals will provide a common starting point for the investigation.  In this case, the primary goal impacted was the fatality and serious injury related to the explosion.  The tank damage and downtime in the facility could also be captured, however we have focused our discussion here on the safety goal impact.

Once we have identified the goals impacted, we can start the analysis by simply asking some “why” questions.  Why was there one contractor fatality and one serious injury?  Because there was an explosion.  Why was there an explosion?  Because there was an ignition source.  Why was there an ignition source? Because contractors were welding on the tank.  “Why” is a great way to get any investigation started, but we also want to expand  the analysis to ensure all the causes are identified (the system of causes, if you will).  In this case, the explosion is caused not just by the ignition source, but also the presence of fuel and the presence of oxygen (think fire triangle).

The ignition source was caused by the welding on the tank, which was being done for repairs and because the workers were unaware of the combustible atmosphere in the tank. The workers were unaware of the combustible atmosphere because there was no atmospheric testing done on the vapor space in the tank because the stickwater was considered to be non-hazardous.  Unlike the oil and gas industry, where the potential for flammable or combustible atmospheres is well known and managed through atmospheric testing, the potential is less well known in industries, such as fish processing, where organic microbiological fluids can release flammable gases, creating a potential risk when doing maintenance work that is spark or heat producing (hot work).   The fuel source for the explosion was methane and hydrogen sulfide being released from the stickwater.  A sample of the material was sent to the lab after the explosion and the presence of these off-gases was identified.  The flammable gases were present because there was 8 inches of stickwater present in the tank.

The Cause Mapping process allows us to identify all the causes related to an incident with the goal of identifying the best solutions to mitigate potential future risk.  Even with this initial analysis, we can start to identify potential solutions to mitigate the risk of this incident occurring again.  Clearly, the potential hazards from flammable atmosphere is not well known in industries with mixtures of water and organic material (e.g. fish processing, pulp processing, potato processing), so lessons learned from this incident, along with others investigated by the CSB, would be worth sharing across the industry.  In addition, requiring atmospheric testing for hot work would mitigate the potential for explosions during these types of maintenance activities. Another option would be to drain and clean the tank prior to welding activities.  These solution could have significant, global impact across all types of hot work activities.