Symptoms, Causes and Root Causes

When something goes wrong at work, the first thing we see is the symptom: the leak, the injury, the late delivery, the wrong invoice. Behind the symptom there is a cause that made it happen. Behind that cause there is often a deeper root cause: the reason the cause was able to happen at all.

Root cause analysis (RCA) is a set of simple methods for finding that deeper reason. The aim is to fix the problem so it does not come back, instead of fixing the same thing again and again.

What each fix achieves

Cleaning the floor fixes the symptom for today. Replacing the hose fixes the cause on one machine. Adding hoses to the inspection plan fixes the root cause on every machine, so worn hoses are replaced before they leak.

Second example. A customer receives the wrong product (symptom). The picker took the item from the wrong shelf (cause). Two similar products have almost identical labels and sit next to each other (root cause). Moving the products apart and changing the labels prevents the same mistake by anyone.