PDCA Improvement Cycle

When to use

Use PDCA for:

• Continuous improvement initiatives (not problem reactions — use 8D for that)
• Implementing a process optimisation with uncertain outcome
• Piloting a change before full deployment
• Structured improvement from lessons learned or audit findings
• Meeting a quality objective that requires a new approach

Key distinction from 8D: PDCA is proactive or slow-burn improvement. 8D is reactive to a specific defect or failure. Both use root cause analysis, but PDCA has a broader scope and a pilot step before full deployment.

When PDCA is used for corrective action (e.g., responding to an audit finding or recurring NC): a Corrective Action Request (CAR) must also be opened to document root cause, actions, and VOE per ISO 9001 §10.2. PDCA is the improvement methodology; the CAR is the governance record.

Prerequisites