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PDCA: The Continuous Improvement Cycle in QHSE Management

PDCA (Plan-Do-Check-Act) is the pillar of continuous improvement in all ISO management systems (9001, 14001, 45001). This article explains its operation and application in QHSE.

IICP HSE Academy Published on 18 October 2026 5 min read 9 views
PDCA — Cycle d'amélioration continue

PDCA: The Continuous Improvement Cycle in QHSE Management

The PDCA (Plan-Do-Check-Act) is the cornerstone of continuous improvement in all ISO management systems (9001, 14001, 45001). This article explains its operation and application in QHSE.

Origin and Definition

The PDCA (Plan-Do-Check-Act), or Deming Wheel, is an iterative cycle for continuous improvement popularized by William Edwards Deming from the 1950s onward. Inspired by the work of Walter Shewhart (1920), it structures the improvement approach for organizations, processes, and management systems.

The PDCA is central to all ISO management standards (ISO 9001:2015, ISO 14001:2015, ISO 45001:2018) and constitutes the pillar of the continuous improvement required by these frameworks.

The Four Phases

1. Plan — Plan

Define objectives, resources, timelines, and responsibilities. Identify risks and opportunities. Construct the action plan. In QHSE, this phase includes risk analysis, policy development, indicator definition, and audit planning.

2. Do — Do

Implement the plan: deploy actions, train teams, document procedures, and apply measures. This phase also includes data collection and monitoring of deviations.

3. Check — Check

Measure results, compare against objectives, analyze deviations, and conduct internal audits. The Check phase enables the objectification of performance.

4. Act — Act

Standardize successes, correct failures, revise the plan, and adjust objectives. This is the improvement phase that closes the cycle and prepares for the next iteration.

Application in ISO Standards

The PDCA structures all operational chapters of the ISO standards:

  • ISO 9001:2015 (quality): chapters 6 (Plan), 7-8 (Do), 9 (Check), 10 (Act)
  • ISO 14001:2015 (environment): same HLS logic (High-Level Structure)
  • ISO 45001:2018 (health and safety): hazard identification, implementation of controls, audit, review

This HLS convergence allows for the integration of management systems into a single QHSE system.

Associated Tools

The PDCA operates in tandem with several QHSE tools:

  • Indicators (KPIs): accident rates, frequency rates, energy consumption, non-conformance rates
  • Internal audits: compliance with ISO 19011:2018 (guidelines for auditing management systems)
  • Management review: annual strategic decision-making
  • Root causes: 5 Whys, Ishikawa diagram, 8D
  • Risk management: ISO 31000:2018 (risk management guidelines)

Concrete QHSE Example

Plan: Reduce the accident rate by 20% in one year. Do: First-aid training, delivery of PPE, workplace audits. Check: Monthly measurement of the rate, analysis of incidents. Act: Rollout, extension to other workshops, adjustment if the objective is not met.

Sources et références

  1. Code du travail marocain (Loi n° 65-99), Titre IV — articles 281 et suivants ILO NATLEX : https://natlex.ilo.org/dyn/natlex2/r/natlex/fe/details?p3_isn=67319

  2. INRS — Démarche d'amélioration continue (portail risques) https://www.inrs.fr/risques.html

  3. ISO 9001:2015 — Quality management systems https://www.iso.org/standard/62085.html

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