At Pump Solutions Australasia, we don’t just sell pumps: we provide pumping solutions. And one of the best solutions to a major problem is called root cause analysis. When a part goes bad, it is tempting to just replace it and keep going. But what about the underlying problem? What made the part go bad in the first place?
Here’s an example of a major pharmaceutical company in the US that could have had a tragedy instead of the “near miss” situation they were able to fix.
At the Eli Lily pharmaceutical plant, a materials basked was being used in a four storey tank. As the basket was being moved to a new location, the cable which held the basket snapped without warning. This caused the basket to fall against the side of the tank. There was nothing in the basket at the time, so there were no injuries.
The incident could have been ignored as minor. The cable could have been replaced and the incident could have been attributed to cable fatigue. In fact, this is just what a lot of companies would have done to keep production going. However, the investigator, Jeffrey S Brown, decided to use a Root Cause Failure Analysis (RCFA)software to find out why the cable really broke.
When the cable originally broke, none of the operators saw anything they felt was unusual. All they saw was a broken cable and a falling basket. However, when the RCFA software was deployed, it was found that one of the major causes of the cable failure was failed safety switches. The cable had a block pulley system which came into contact with the cable drum. This caused the cable to snap.
When the cable was tested for strength, it was found to be well within manufacturer’s specifications. In other words, the cable itself wasn’t a factor.
The Five P’s System
Are we suggesting you go out and buy software? No, but we do want you to know about the Five P’s system of root cause analysis. The five P’s stand for “parts, position, paper, people and paradigms.” While the data in this case was collected by software, the method is sound and can be used to get great results without software.
In this case, “parts” meant collecting the broken parts and also inspecting parts that may or may not have been affected by the process but were connected to it somehow. It is important to inspect all relevant parts before they are replaced or thrown out.
“Position” meant taking photos of the exact position of all of the equipment at the time of the incident. Position is important because small differences in position can greatly affect the outcome. This technique is used in many investigations over many different fields.
“Paper” meant having access to the latest data on when parts were last maintained or replaced, a manual for the system, a Job Safety Analysis and a recent inspection report.
“People” meant interviewing everyone present during the incident. It also involved interviewing those who had inspected the cable, the switches and any other parts.
“Paradigm” is an important part of the process, too. In this case, the paradigm was that “the switches had never failed before, so they won’t fail now.” It also involved the cable having an emergency switch that would reverse the direction of the pulley block, preventing contact with the drum.
Ultimately, it was found that when the pulley block contacts the drum, it creates a locked rotor position. This greatly increased torque, which was enough to cause the cable to snap. The safety switches were analyzed and were found to have not activated in time to prevent the incident.
Thanks to the root cause analysis, the facility was able to increase the distance between the block and the drum, providing what they called a “safety area” and giving the switches more time to activate. They also modified the Standard Operating Procedure for the materials basket.
What it Means for Your Pumps or Pumping Systems
We always recommend at least an elementary form of root cause analysis when any piece of equipment malfunctions. We are happy to help you replace your pumps parts, but we would much rather see you solve the problem.
To learn more about high quality pumps, call Pump Solutions Australasia today: 1300 793 418.