Monthly Archives: November 2014

Root Cause Analysis - Incident Investigation

Chocolate Makers Warn of Possible Shortage

By Kim Smiley

Chocolate is one of the most beloved foods, but it may be becoming a little too popular.  Major chocolate makers have warned of a possible chocolate shortage looming in the near future.  According to a recent article by the Washington Post, “The world’s biggest chocolate-maker says we’re running out of chocolate”, the world consumed about 70,000 metric tons more cocoa last year than it produced.  The chocolate deficit is also predicted to get worst.

The chocolate shortage is a classic example of supply and demand in action.  The demand for cocoa is rising at the same time that the supply is dropping.  The price consumers are paying for chocolate is already increasing and is likely to get significantly higher if these trends continue.

So why is demand increasing (beyond the obvious fact that chocolate is delicious)? Part of the answer is that it is trendy to include chocolate in a wider variety of foods such as savory gourmet dishes, liquor and breakfast cereal.  Even the already questionable potato chip has been covered in chocolate to the delight of many.  The increasing popularity of dark chocolate also comes into play because dark chocolate contains significantly more cocoa than typical chocolate. (An average chocolate bar is about 10% cocoa while dark chocolate bars are usually closer to 70%.)  The sheer number of people who are eating chocolate is also growing as chocolate is more widely available worldwide, particularly in Asia where chocolate consumption is increasing rapidly.

While demand continues to grow, supply is decreasing.  Drought in West Africa, where the majority of the world’s chocolate is grown, has impacted the cocoa supply.  The plants are also being attacked by diseases; the most noteworthy is a fungus called Frosty pod, which is reducing the crop further.  The nature of chocolate trees also makes responding to difficult or changing growing conditions challenging because it takes them years to mature.  With the difficulties facing chocolate trees, many farmers are turning to other crops that are more profitable which reduces the production of cocoa.

The end result of higher demand for chocolate will likely be further increases in the price of chocolate.  It’s also likely that chocolate makers will continue to develop candy that includes non-chocolate ingredients such as nuts, raisins or nougats to meet the demand for treats while using less actual chocolate.  Additionally, farmers are working to develop new strains of cocoa that are resistant to disease and drought and/or produce more cocoa per plant, which would increase the supply of cocoa.

A Cause Map, a visual root cause analysis, can be used to show the causes that have contributed to the chocolate deficit. To view a high level Cause Map of this example, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

Investigation Into the Fatal Crash of Commercial Space Vehicle is Underway

By Kim Smiley

On October 31, 2014, Virgin Galactic’s commercial space vehicle, SpaceShipTwo, tore apart over the Mojave Desert in California during its fourth rocket-powered test flight. One pilot was killed and the other seriously injured. An investigation is underway to determine exactly what caused the crash, but initial data indicates that the tail booms used to slow down the vehicle moved into the feathered position prematurely, increasing the aerodynamic force. This disaster has the potential to impact the emerging commercial space industry as regulators and potential passengers are reminded of the inherent dangers of space travel.

This issue can be analyzed by building a Cause Map, a visual method for performing a root cause analysis. An initial Cause Map can be built using the information that is currently available and then easily expanded as more data is known. The first step is to fill in an Outline with the basic background information of the incident. Additionally, the impacts to the overall goals are listed on the Outline to determine the scope of the issue. The Cause Map is then built by asking “why” questions.

Starting with the safety goal in this example: one pilot was killed and another was injured because a space vehicle was destroyed and they were onboard. (When two causes both contribute to an effect, they are both listed on the Cause Map and joined with an “and”.) SpaceShipTwo is designed to hold passengers, but this was a test flight to assess a new fuel so the pilots were the only people onboard. The space vehicle tore apart because the stress on the vehicle was greater than the strength of the vehicle. The final report on the accident will not be available for many months, but the initial findings indicate that the space vehicle experienced greater aerodynamic forces than expected.

The space vehicle used tail booms that were shifted into a feathered position to increase drag and reduce speed prior to landing. Video shows the co-pilot releasing the lever that unlocked the tail booms earlier than expected while the vehicle was still accelerating. It’s unclear at this time why he released the lever. The tail booms were not designed to move when unlocked and a second lever controls movement, but investigators speculate that the aerodynamic forces on the space vehicle while it was still accelerating caused them to lift up into the feathered position once they were unlocked. The vehicle disintegrated seconds after the tail booms shifted position, likely because of the aerodynamic forces in play.

After the final report is released, the Cause Map can be expanded to include the additional information. To view a high level Cause Map of this accident, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

Safety Concerns Raised by 5 Railroad Accidents in 11 Months

By ThinkReliability Staff

The National Transportation Safety Board investigates major railroad accidents in the United States. It was not only the severity (6 deaths and 126 injuries) but the frequency (5 accidents over 11 months) of recent accidents on a railroad that led to an “in-depth special investigation“. Part of the purpose of the special investigation was to “examine the common elements that were found in each”.

When an organization sees a recurring issue – in this case, multiple accidents requiring investigation from the same railroad, there may be value in not only investigating the incidents separately but also in a common analysis. A root cause analysis that addresses more than one incident is known as a Cumulative Cause Map, and it captures visually much of the same information in a Failure Modes and Effects Analysis, or FMEA.

The information from the individual investigations of each of these accidents can be combined into one analysis, including an outline addressing the problems and impacts to the goals from the incidents as a whole. In this case, the problems addressed include issues on the Metro-North railroad in New York and Connecticut from May 2013 to March 2014. The five incidents during that time period resulted in 4 customer deaths and 126 injuries, 2 employee deaths, and over $23.8 million in property damage.

The analysis of the individual accidents can be combined in a Cumulative Cause Map to intuitively show the cause-and-effect relationships. The customer deaths and injuries, and the property damage, resulted from train derailments and a collision. The train collision resulted from a derailment. In two of the cases, the derailment was due to track damage that had either been missed on inspection or had maintenance deferred. In the third derailment (discussed in a previous blog), the train took a curve at an excessive rate of speed due to fatigue of the engineer. Inadequate track inspections and maintenance, and deferred maintenance were highlighted as recurring safety issues to the railroad.

Both of the employee fatalities resulted from workers being struck by a train while performing track maintenance. In one case, the worker was outside the designated protected area due to an inadequate job safety briefing. In the other, a student removed the block while working unsupervised, allowing a train to travel into the protected area. The NTSB also identified inadequate safety oversight and roadway worker protection procedures as areas needing improvement. While the NTSB already released recommendations with each of the individual investigations, it plans to issue more based on the cumulative investigation addressing all five incidents. View an overview of all 5 incidents by clicking “Download PDF” above.

Root Cause Analysis - Incident Investigation

Antares Cargo Rocket Explodes Seconds After Launch

By Kim Smiley

On October 28, 2014 an Antares cargo rocket bound for the International Space Station (ISS) catastrophically exploded seconds after launch.  The $200 million rocket was planned to be one of eight supply missions to the ISS that Orbital Sciences has a $1.9 billion contract to provide.  The investigation is still underway, but initial findings indicate that there may have been a problem with the engines, which were initially built in the 1960s and early 1970s by the Soviet space program.

Whenever NASA launches a rocket, it is observed by safety personnel with the ability to cause the rocket to self-destruct if it appears to be malfunctioning to minimize potential injuries and property damage. Reports by NASA have indicated that this flight-termination system was engaged shortly after liftoff in this case because the rocket malfunctioned shortly after takeoff.

Video of the launch and the subsequent explosion show the plume from one engine changing shape a second before the massive explosion.  The change in the plume has led to speculation that a turbopump failed shortly after liftoff and suggests that the engines were the source of the malfunction.  Investigators are currently reviewing the video of the launch, telemetry readings from the rocket, and studying the debris to learn as many details as possible about this failure.

The engines in question are NK-33 rocket engines that were initially built (not just designed, but actually manufactured) more than 4 decades ago. So how did engines from the Apollo era end up on a rocket decades later in 2014?  The one-word answer is money.

These engines were originally designed to support the Soviet space program which was disbanded in 1974.  For years, these engines were warehoused with no real purpose.  In 1990, these engines were sold to a company called Aerojet, reportedly for the bargain price of a cool million each.  The engines were refurbished and renamed Aerojet AJ-26s.  The cost of using these older engines was significantly less than developing a brand new rocket design.  In addition to being expensive, a new rocket design requires a significant time investment.  There are also limited alternatives available, partly due to NASA’s shrinking budget.

Orbital Sciences has announced that they will source a different engine and no longer use the AJ-26s, but it’s worth nothing that these rockets have been used successfully in recent years. They have launched Cygnus supply spacecraft three times without incident.

To view a high level Cause Map, a visual root cause analysis, of this incident, click on “Download PDF” above.