Failure Mode and Effects Analysis

Learning objectives

• Build a process FMEA distinguishing failure, effect and cause.
• Rate severity, occurrence and detection consistently.
• Prioritise prevention over detection.

How FMEA works

For each process step, list failure modes, effects on the customer, causes and current controls. Rate severity, occurrence and detection using defined scales, then use action priority or RPN with care.

High-severity items deserve action even when the total score is not the highest.

Garment-factory example

‘Wrong size label attached’: effect = customer return (severity 9); causes include bundle mix, scanner bypass; prevention controls = barcode gate; detection controls = end-line audit.

Method

1. Map the steps and identify modes.
2. Rate S/O/D against agreed definitions.
3. Prioritise high-severity risks first.
4. Reassess residual risk after actions.

Common mistakes

• Changing scores without changing the process.
• Using RPN as the only priority rule.