Concept

What is Occurrence and Escape Root Cause?

In 30 seconds

A problem usually has two separate root causes: the occurrence cause (why did the defect happen?) and the escape cause (why did it reach the customer without being caught?). Many practices add a systemic cause as well.

How does it work?

  • The occurrence cause is sought in the process: parameters, tooling, material, method.
  • The escape cause is sought in the control system: control plan, measurement, error-proofing.
  • A separate corrective action is defined for each.

Often confused with

The single-cause trap

Fixing occurrence reduces the chance of the same defect; fixing escape also reduces the chance of other defects reaching the customer.

Common mistakes

  • Addressing only the occurrence cause.
  • Reducing the escape cause to a personal one such as "the check was skipped".

From a QWorks perspective

In QWorks occurrence and escape causes are analysed in separate tabs, and each one’s action and evidence are tracked separately.

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