What is Root Cause Analysis
Root cause analysis (RCA) is the process of finding the real, underlying cause of a problem so that it can be fixed permanently. Fixing the symptom (like reworking a defective piece) solves the case once. Fixing the root cause (like correcting the machine tension) prevents the problem from happening again.
Why RCA Matters
In garments, most problems repeat. The same defect keeps appearing. The same machine keeps breaking. The same shipment keeps getting delayed. RCA breaks this cycle by finding the true cause and eliminating it.
Common RCA Tools
5 Why is the simplest. Fishbone diagram shows possible causes. Pareto chart shows which cause matters most. Scatter plot shows relationships. Control chart shows stability. FMEA predicts failures. Use 5 Why and fishbone for most daily problems.
Practical Example 1 — Recurring Defect
Defect: puckering on shoulder seam, recurring weekly. RCA: the machine tension dial was not calibrated. The machine had been adjusted by different operators. Root cause: no tension calibration standard. Fix: standard tension setting and daily check.
Practical Example 2 — Late Shipment
Shipment late by 4 days, third time this quarter. RCA: fabric in-house date is always 5 days later than planned. Root cause: fabric supplier lead time is quoted at 30 days but actual is 40 days. Fix: update supplier lead time and re-plan capacity.
Practical Example 3 — High Absenteeism
Absenteeism 9 percent, highest in the factory. RCA: most absences are on Saturdays. Root cause: no transport on Saturday afternoons. Fix: add transport on Saturday. Absenteeism drops to 4 percent.
Practical Example 4 — Machine Breakdown
Needle breakage every 3 days. RCA: needle size mismatch for thick fabric. Root cause: needle selection guide is not posted at the machine. Fix: post a needle selection chart and train operators.
Steps in RCA
Define the problem clearly with data. Gather evidence and observe the process. Use fishbone to list possible causes. Use 5 Why on the top 3 causes. Verify the root cause with data. Design and implement a countermeasure. Monitor results for 2 weeks. Standardize and share the learning.
Common Mistakes
Jumping to a solution before finding the cause. Blaming people instead of systems. Stopping at the first plausible cause. Not verifying with data. Not following up after the fix.
When to Use It
RCA is used for every recurring problem: defects, breakdowns, delays, absenteeism, efficiency drops, and safety incidents. It is the foundation of any serious continuous improvement program.