Root Cause Analysis for Minor Defects
Root cause analysis can be useful for near misses and recurring minor defects as well as major failures. In high-volume processes, a small defect can accumulate into substantial harm or cost.
THE IDEA
Can Root Cause Analysis Be Applied to Minor Defects? Insights from Lean Ways of Working
It should be self‐evident that if something catastrophic happens or things show only a slight improvement over time (e.g. a pipe keeps leaking), this is a time to do a root cause analysis (RCA).
And, if there is a ‘near miss’ (where nothing bad has happened yet, but something bad nearly happened), this can also be a time to consider an RCA, because it may be the only warning you get before something much worse happens.
Over a period of time, Lean manufacturing insights highlighted that if you do something frequently, even the smallest defect might become a big deal (e.g. if you were to have a faulty air bag installed in thousands of cars) and so might merit an RCA, to avoid problems accumulating.
When to use it
Investigating a recurring minor defect in a manufacturing line to prevent cumulative waste.
Analyzing near misses in healthcare to prevent future patient safety incidents.
Applying RCA to small but frequent customer complaints to identify systemic issues.
Deciding when to escalate a seemingly trivial problem to a full RCA in a lean operation.
FROM THEORY TO EVERYDAY LIFE
In practice
Near Miss in a Chemical Plant
A chemical plant experiences a small leak that is contained quickly. No harm occurs, but a root cause analysis reveals a corroded valve. Repairing it reduces the risk of a more serious release.
Minor Defect in Automotive Assembly
An assembly line produces cars with a slightly misaligned door seal. Individually trivial, but over thousands of cars it leads to wind noise complaints and warranty costs. RCA identifies a calibration drift in the robotic arm.
A MOMENT TO REFLECT
Put it to work.
Think of a recent minor issue at work or home that could escalate. What would a root cause analysis reveal?
How do you decide whether a near miss warrants a full RCA versus a simpler corrective action?
What criteria can you use to prioritize minor defects for root cause analysis in a high-volume process?
CONTINUE THE CONVERSATION
Source texts
- Beyond the Five Whys Root Cause Analysis and Systems Thinking (James C. Paterson)