Root Cause Analysis

YOUR need to eliminate the CAUSE of the problem...
Acton EMS has a huge database to trouble shoot with future prevention.

WHAT IS RCA ?

A root cause analysis is a methodology to identify the root cause of a given problem or issue, by asking a serious of questions.  These questions prompt us to consider different viewpoints.  Each of these viewpoints will either confirm or conflict with the initial viewpoint.

PLEASE CLICK ON IMAGE TO ENLARGE.

It is a proactive technique to eliminate reactive thinking and clearly see what caused what to happen.

Why it's useful - Root Cause Analysis is helpful

  • To prevent a recurrence of the same failure
  • To ensure that valuable time is not wasted by implementing solutions to symptoms rather than causes.
  • As a teaching aid for technicians - we learn deeper thinking about how a machine works by thinking through what caused this one to fail.
  • To prevent a recurrence of other similar Assets.

HOW to use it... It is simpler to use than it looks !

  1. Start by looking at the most obvious failed component
  2. Next ask did this fail due to the failure of another internal component
  3. Yes to Q2 goes back to 1
  4. No to Q2 asked the question did this fail due to an external influence
  5. Yes to Q4 asks - Was this external influence caused by a different external influence
  6. No to Q5 take you to conclusion
  7. Yes takes you back to the 5th bullet
  8. If you get a maybe you have to go back to 1st bullet

Conclusion is that the internal/external cause has been identified.  We need to decide what to do to prevent its recurrence.

EXAMPLE - Root cause of Failure

  • Winding wire enamel has been overheated  in an even pattern (Black is>250 Deg C)
  • Did this happen due to another internal component failure
  • No the normal colour winding was still intact with good connections to the motor
  • Terminals, and would have taken current if any was applied.. clearly had little or none because it was not overheated
  • No on Q2 This appears to have failed due to loss of supply to the one clean phase of the motor
  • Yes to Q4 Was the loss of supply due to another external influence (gathered information from the trouble shooter he said the one fuse link was blown, was a green fuse, not motor rated
  • Ask was this wrong fuse due to some other external influence
  • Yes to Q7 the operator overloaded the motor last month and blew a fuse and put in the only fuse he had
  • Is there any other external reason which caused the operator to put in the wrong fuse
  • Yes - The overload device was set 20% high and did not operate
  • Why was the overload device set high? Production had been testing a new product at its top speed an dit kept tripping out
  • Was there any other external cause beyond this - No

Conclusion:

  • Train the operator to call the Electrician, or fit fuses of the same type as removed.
  • Put a sign on the fuse board “when replacing fuses only fit identical rating fuses”
  • Train the Operator and Electrician to check the fuse rating if making adjustments to overload ratings.
  • Fit a more modern overload - capable of tripping when a fuse blows, even when the rating is adjusted up.