Titanic Sinking |
Cause Mapping®: Effective Root Cause Analysis
Cause Map: Titanic Sinking
Why did the Titanic sink? Being a systems problem, there is no right answer to this question. There is not one cause but many. Nevertheless, most people believe incidents have one cause, and finding that cause is what investigators do. As you will see, this is far from the truth.
Step 1: Defining the Problem (Problem Outline). Going back to the first step of Cause Mapping, investigators must define the problem by asking the four questions: what, when, where, impact to the goals. First, consider the “What.” What was the problem? One person may say that the problem was that the Titanic sank. Another might say that the problem was that it hit an iceberg; a third could say the ship was filled with water. Seemingly similar, there are subtle differences between these answers representing different ways to define the problem. In the Cause-Mapping methodology the facilitator anticipates that the group may disagree, so all three responses are written down. There is no need to spend time debating the problem. The magnitude of this problem is defined by the impact to the goals, as described below. Now consider “when,” or “When did the incident take place?” This captures the time of the incident, along with what was different or unusual, something fundamental to any investigation. On the Titanic, we capture the date and times, and unusual elements as follows:
- April 14, 1912, 11:40 p.m., when the iceberg was hit
- April 15, 1912, approximately 2:20 a.m., when the ship was under the surface
- Unusual Events: Maiden Voyage, Late Spring, Iceberg Warnings.
Next comes “where,” or, “Where did the incident take place?” Several pieces of information emerge here. First comes, of course, the incident’s physical and geographic location, along with the so-called “process” location. For the Titanic, the location contains the name of the company and the business (White Star Line, England), and the geographic location includes the latitude and longitude of the actual crash into the iceberg. The physical location is the right side of the hull that struck the iceberg—compartments 1 through 6 are specified. The “process” location defines where in the process the incident occurred. The Titanic went through many “processes,” from docking and maintenance to fueling. The problem at hand, of course, occurred not when it was fueling or docking, but when it was en route from Southhampton, England, to New York City. The next section involves the impact to overall goals. First, let’s define those goals. On a passenger vessel, one goal would be to have zero injuries; another, no damage to the vessel. Every employee at White Star Line, from the yard worker to the board member, would agree to these goals. (That is, when asked, “Do you want zero injuries on your ships?” every person in the organization would answer “yes.”) On the Titanic, more than 1,500 out of 2,200 onboard lost their lives and the vessel was, of course, lost. There were other goals that were affected. But the loss of life has such magnitude that any other goal bears less significance. So here, we’ll work with two: safety (i.e., the goal of zero injuries) and the vessel (the goal of no damage). Step 2: Analysis (Cause Map). This involves the construction of the Cause Map. It starts by writing down the goals that were affected as defined in problem outline. For the Titanic, the safety goal was impacted due to the 1,500 fatalities; the vessel goal was impacted because the entire ship was lost. These represent the first two cause-and-effect relationships in the analysis.
The analysis continues by asking the “why” questions and moving to the right of either cause-and-effect relationship. In this example, we’ll start with the loss of 1,500 lives, which was caused by the Titanic sinking. The next question is, “Why did the Titanic sink?” Typical responses to this question are because it hit an iceberg and because it filled with water. Although there are two different answers to this one question, both are valid and can be added to the Cause Map. The Titanic sank because it filled with water; the ship filled with water because the steel plates buckled on the hull, which was due to the ship hitting the iceberg. The cause-and-effect is mapped as follows: Here, step back: Is the iceberg (i.e., stress from the impact) the only cause for the steel plates buckling? True, for steel plates to buckle requires stress; but they also buckled due to an inherent lack of strength. This, in fact, makes two causes to the steel plates buckling: the fact that the ship hit an iceberg, and that the steel’s strength wasn’t sufficient to prevent the buckling: Since the strength of the steel and the force of the ship hitting the iceberg were both required for the steel plates to buckle on the hull, either cause can be controlled to prevent and, in turn, reduce the risk of the effect. The Cause Map can extend to the right again, showing some of the causes of the ship hitting the iceberg. Moving back over to the left, it also adds another cause, branching out from our initial and most important effect: the loss of 1,500 lives. This not only happened because the Titanic sank but also because the ship did not have enough lifeboats. Even if the Titanic sank in the same manner that it did, adding more lifeboats—even just one— would have reduced the risk of 1,500 people dying. How much that risk would be reduced depends on the number of lifeboats added, among other factors (staff training, evacuation drills, etc.). Note the three causes behind the ship hitting the iceberg: The iceberg had to be in the path of the ship, the ship had to be in the water and the ship had to not turn enough to miss the iceberg. All of the causes were required to produce the effect ship hit iceberg. Controlling any one of the causes, such as turning ship sufficiently, reduces the risk the ship hitting the iceberg and, ultimately, losing 1,500 people. As unusual as it may sound, some people may argue that if the Titanic were never put in the water, the ship wouldn’t have sank. People are willing to argue the point because it is true. This illustrates a great benefit of a Cause Map: It’s a venue for getting all causes on the table. The process assumes nothing because, if it did, causes—and, hence, potential solutions—may be missed. And even if the cause doesn’t lead to any solution, disagreeing with the person arguing the point creates unnecessary debate that may take several minutes. The fact that the Titanic was allowed in the water is indeed a cause, so take 15 seconds to add it to the Cause Map, then continue with further detailed analysis. The following Cause Map shows that the Titanic sinking also causes the loss of the entire ship, which impacts the goal of no vessel damage. Among other elements this map shows: · Detail behind to the strength of the steel illustrates that hull strength is a function of not only the design of the hull but also the strength of the steel · The ship didn’t turn sufficiently because of its speed, the fact that iceberg was seen too late and the size of the rudder. The simple cause-and-effect relationship of the Titanic sank because it hit an iceberg is accurate; it’s just not as thorough as the more detailed Cause Map. All this illustrates the benefit of dissecting the cause and effects behind serious problems. Organizations that don’t know how to break a problem down into specific cause-and-effect relationships mistakenly oversimplify a complex incident by providing oversimplified solutions—such as “don’t hit icebergs.” Shown here, at a high level the Titanic tragedy has only one cause. At a more detailed level it has 5 causes, 19 causes and 115 causes. All of the levels of the Cause Map are accurate; some simply have more detail that others. As with any investigation, the level of detail depends on the incident’s effect on the organization’s overall goals. With the loss of life, the Titanic incident had quite an effect. It was investigated by the United States and the United Kingdom. And after the tragedy, the International Maritime Organization implemented specific action items that became the Safety of Life at Sea (SOLAS) convention. In fact, all of the actual action items that emerged from the Titanic tragedy can be matched directly to specific causes on a detailed Cause Map. (Note: A detailed Cause Map of the Titanic incident with more than 100 causes can be found at www.thinkreliability.com.). After the Cause Map is built to a sufficient level of detail with supporting evidence, the search for solutions begins. The Cause Map helps identify all possible solutions for given issue, so that the best solutions can be selected. The more detailed the Cause Map, the more possible solutions may be identified. And the more possible solutions, the greater chance the best solutions will emerge. It is easier to identify many possible solutions from the detailed Cause Map than the oversimplified high-level analysis. An issue should be worked to a sufficient level of detail to prevent the incident, reducing the risk of the incident occurring to an acceptable level. Lower-risk incidents will have investigations requiring fewer details than those in higher-risk environments. This is why, of course, solutions at a coffee shop are not as thorough or detailed as an airline or nuclear power facility. The Potentials of a Cause Map The Cause-Mapping approach focuses on the basics of the cause-and-effect principle so that it can be applied consistently to day-to-day issues as well as catastrophic, high-risk events. The steps of Cause Mapping are the same, but the level of detail for each is different. Focusing on the basics of the cause-and-effect principle make the Cause-Mapping approach to root cause analysis a simple and effective method for investigating safety, environmental, compliance, customer, production, equipment or service issues. At an even higher level, Cause Mapping can be part of continual process improvement, striving for the ideals behind the overall goals. To this end, the Cause Map can complement so-called “process maps,” which spell out specific steps in a work process, defining how an organization would like to conduct business every day. A process map helps show that a problem exists (e.g., inefficiencies, waste, etc.); a Cause Map, in turn, defines the problem and finds solutions that make specific changes to the process map. When another problem occurs, another Cause Map is drawn up, and the cycle starts again. This continual cycle can push an organization toward more efficiency, better quality and, in the end, greater success. |