pdca-improvement

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

• Improvement goal defined (with target metric)
• Baseline data available (current performance)
• Owner and resources assigned

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Workflow

PLAN — Analyse and define the approach

1. Define the current situation

   • What is the problem or improvement opportunity?
   • What is the current measured performance? (baseline)
   • What is the target? (SMART: Specific, Measurable, Achievable, Relevant, Time-bound)

2. Analyse root cause

   • Use Fishbone and 5-Why to understand why current performance is below target
   • Use data: Pareto charts, run charts, capability studies

3. Develop the improvement plan

   • What specific actions will close the gap?
   • Who is responsible for each action?
   • What is the timeline?
   • What resources are needed?
   • What risks does the change introduce? Review the applicable PFMEA — does this change add or remove a failure mode? Does it affect any existing prevention or detection control?

4. Define the pilot scope

   • Which process, line, or area will pilot the change?
   • What volume or duration is needed to validate effectiveness? Define this before starting the pilot — do not decide after seeing results.
   • What will you measure, and how?