Root Cause Analysis
• Root Cause Analysis is a method that is used to address a problem or non-conformance, in order to get to the “root cause” of the problem. It is used so we can correct or eliminate the cause, and prevent the problem from recurring. • Traditional applications of Root Cause Analysis – Resolution of customer complaints and returns. – Disposition of non-conforming material (Scrap and Repair) via the Material Review process. – Corrective action plans resulting from internal and customer audits.
• Through this training course, you will:
– Understand the meaning of “Root Cause” – Know the steps used to identify the root cause of problems.
What is Root Cause?
• Root Cause is the fundamental breakdown or failure of a process which, when resolved, prevents a recurrence of the problem. Or, in other words
• For a particular product problem, Root Cause is the factor that, when you fix it, the problem goes away and doesn’t come back. • Root Cause Analysis is a systematic approach to get to the true root causes of our process problems.
Philosophy of Root Cause Analysis
• Each problem is an opportunity (“golden nugget”) because it can tell a story about why and how it occurred. • It is critical that everyone take a personal and active role in improving quality. • The “true” problem must be understood before action is taken. – Problems are often masked for a variety of reasons
• To do this well, we must be – Both focused and open-minded – Both patient and quick – Above all, we must be relentless 5
We Perform Root Cause Analysis to Prevent Turnbacks and Customer Escapes from Recurring Defects found at: Own Next Process Process Step Step Later Process Step Before Reaching Customer Found By Customer
Cost: $1 Very Minor $10 Minor Delay $100 Rework $1,000 Significant Rework
$10,000 Warranty Cost Admin. Cost Reputation Loss of Market Share 6
Reschedule Delay in of Work Delivery Additional Inspection
Symptom Approach vs. Root Cause
• If we do a poor job of identifying the root causes of our problems, we will waste time and resources putting bandaids on the symptoms of the problem.
• “Errors are often a result of worker carelessness.” • “We need to train and motivate workers to be more careful.” • “We don’t have the time or resources to really get to the bottom of this problem.”
• “Errors are the result of defects in the system. People are only part of the process.” • “We need to find out why this is happening, and implement mistakeproofs so it won’t happen again.” • “This is critical. We need to fix it for good, or it will come back and burn us.”
How do we do Root Cause Analysis?
• Said simply, Root Cause Analysis is asking why the problem occurred, and then continuing to ask why that happened until we reach the fundamental process element that failed. Why???
• The following example illustrates the basics of Root Cause Analysis.
Fishbone Diagram - A Useful Tool
• Using a fishbone diagram while brainstorming possible causes helps you to focus on the various possibilities. Some useful categories: Materials People Instructions Environment
Example: The Washing Machine
Problem Description Problem Description “Machine is 2 weeks old “Machine is 2 weeks old (Serial #2345017). When (Serial #2345017). When doing the fourth load of doing the fourth load of clothes, IIheard aaloud noise clothes, heard loud noise and the machine stopped! It and the machine stopped! It wouldn’t re-start.” wouldn’t re-start.”
Verify the Complaint
Problem Verification Problem Verification Service technician checks Service technician checks washing machine operation washing machine operation to test procedure (#8496). to test procedure (#8496). The machine does not The machine does not operate. operate.
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