Wednesday, May 28, 2008

Root Cause Analysis, Part 2

Photos from

In an earlier post, I used the 5-why technique to determine the root cause of the RMS Titanic hitting an iceberg: communication error between the watchman and his officer regarding the availability of binoculars. While this is truly a root cause, it doesn't inform us why the Titanic, billed to be "unsinkable," sank in less than three hours once it hit the iceberg. So the next question is, once it hit the iceberg, why 1, why did it sink so quickly?

The answer to this first why unfolds in a new book called "What really sank the Titanic." In it, the authors present results of submarine recon showing the ship sank so quickly due to rivets popping along the six slits opened in the seams on the bow of the Titanic. So the next question, why 2, is why did the rivets pop?

Research indicates that the rivets used were poorer quality than standard, causing an easy fracture path for failure. The research was conducted on many rivet samples retrieved from the shipwreck site. Photomicrographs show the phosphate and sulphate inclusion level in these iron rivets is excessive, leading to a weaker fastening of the ship. You can see this on the scanning electron micrograph, shown below from, which shows a long slag inclusion provided a fracture path for this rivet's failure.

So the next question, why 3, is why the poor quality rivets were used?

These lower quality rivets were used because of a scarce supply of top quality rivets. Research on meeting minutes cites repeated references to shortages of "best best" quality rivets. So the next question, why 4, is why there was a scarce supply?

The shipbuilder, Harland & Wolff, was building three ships the size of Titanic at the same time. The Britannic and the Gigantic were ships in the same series as the Titanic, and all three were under construction at the same time. Which begs the final question, why 5, why were they building three huge ships at once?

This was a policy decision made by managers at Harland and Wolff. The basic motivator is the drive for profits which, in this case, trumped the need for quality. So to avoid the sinking of the Titanic, an executive at Harland and Wolff would have had to say, “no, we cannot meet this schedule and build the three ships safely with materials that are currently available, so we must delay one or two of the ships.” This would have allowed proper materials to be used and would have saved 1520 lives.

This analysis shows that most problems are the cause of policy decisions and ineffective management, not workers like watchmen or riveters. It was an officer who didn’t supply the binoculars, it was an executive who specified the wrong rivets rather than changing the schedule.
The root cause of the Titanic's sinking so quickly was an executive decision far removed from the sinking, both in space and time; As Deming said, “The problem is at the top, management is the problem.”


Zul Fadhli said...

Agreed 110% that 5-why will direct us towards problems solving. Therefore downliners need to be trained so that company direction will be as the same

uh2l said...

Not only do decisions at the top lead to major issues or catastrophes, but lack of process and controls which can replace decisions are often also at fault. Neat blog. I Googled "Idea Power" as a slogan for my company which will license product ideas.

Take it easy,