What is the PDCA Cycle? #
The PDCA Cycle (Plan–Do–Check–Act) is a continuous improvement framework used in management systems like ISO 45001 to systematically manage processes and risks related to Occupational Health & Safety (OH&S). It ensures an organization can continuously improve its OSH performance and meet intended outcomes.
This approach is embedded in ISO 45001:2018 and enables organizations to proactively manage risks, fulfill legal requirements, protect worker health and safety, and promote a culture of prevention.
The 4 Phases of the PDCA Cycle in ISO 45001 #
The ISO 45001 structure is built around 10 clauses (see Annex SL structure), but core implementation revolves around Clauses 4 to 10 aligned to PDCA, as illustrated in your provided images:
PLAN (Clauses 4, 5, 6) #
“Establish the objectives and processes necessary to deliver results in accordance with the organization’s OH&S policy.”
- Clause 4: Context of the Organization
Understand internal & external issues (4.1), needs and expectations of workers & other parties (4.2), define the scope of the OSHMS (4.3) & OH&S management system (4.4).
➤ This forms the foundation for risk-based thinking and system boundaries.
➤ To effectively plan the Occupational Health and Safety Management System (OHSMS), organizations must first establish a solid understanding of their internal and external environment. This includes identifying all relevant factors that can affect the organization’s ability to achieve intended OH&S outcomes. Organizations need to analyze both internal factors (such as company culture, roles, governance, processes, and resources) and external factors (such as legal requirements, economic conditions, labor market, and industry risks).
➤ Alongside this, the organization must identify and understand the needs and expectations of workers and other interested parties—including regulatory bodies, contractors, suppliers, customers, and the general public. Some of these needs may become compliance obligations if the organization chooses to adopt them or is legally bound to do so.
➤ Based on this understanding, the organization is required to define the scope of its OH&S Management System. This means determining what parts of the organization will be included in the system based on the operational context, stakeholder expectations, and nature of work. The scope must be appropriate, realistic, and clearly documented.
➤ Finally, the organization must establish and maintain an OH&S Management System that is capable of achieving its objectives, meeting legal and regulatory requirements, and supporting continuous improvement. This includes setting the system’s foundation for risk-based thinking, proactive planning, and clear system boundaries.
. - Clause 5: Leadership & Worker Participation
Top management must demonstrate commitment, define the OH&S policy, assign roles & responsibilities, and ensure worker consultation and participation.
➤ Worker involvement is a cornerstone of ISO 45001:2018, ensuring that the Occupational Health and Safety Management System (OHSMS) is both relevant and effectively implemented. Leadership must go beyond top management directive and foster a culture where workers are actively engaged at all levels.
➤ Demonstrating Commitment to OH&S
Top management must lead by example and actively involve workers to demonstrate their commitment to the OH&S policy and continual improvement of the system.
➤ Defining the OH&S Policy
Workers should be consulted during the development of the OH&S policy to ensure it reflects real workplace conditions, risks, and needs. This increases policy relevance and ownership at all levels.
➤ Assigning Roles, Responsibilities, and Authorities
The organization must clearly define and communicate roles and responsibilities for OH&S. Importantly, this process must involve workers to ensure clarity and accountability, especially for those responsible for reporting hazards or participating in incident investigations.
➤ Consultation and Participation of Workers
ISO 45001 emphasizes the need for both consultation (seeking input before decisions are made) and participation (involvement in decision-making and implementation).
Workers must be involved in:
– Identifying hazards and assessing risks.
– Determining controls.
– Incident investigation and reporting.
– Audits and continual improvement actions.
➤ Empowerment and Protection of Workers
Workers must feel empowered to raise safety concerns without fear of retaliation. The system must promote trust, transparency, and open communication, which are vital for proactive risk management.
➤ Inclusion of Non-Managerial Workers
Clause 5 explicitly requires the involvement of non-managerial workers, ensuring their voices are heard—especially those working closest to the hazards.
📝 Summary
Worker involvement in ISO 45001 is not optional—it is essential. It ensures the OHSMS is not just a top-down directive but a living system co-created with those who face workplace risks daily. This active engagement ensures better hazard identification, stronger control implementation, higher policy relevance, and ultimately, improved safety performance.
. - Clause 6: Planning
Identify and assess risks & opportunities (6.1), set OH&S objectives (6.2), and plan actions to mitigate risks and fulfill compliance.
➤ Clause 6 of ISO 45001:2018 plays a critical role in realizing the effectiveness of the “Plan” phase within the PDCA cycle by embedding a structured and proactive approach to occupational health and safety management. It begins with identifying and assessing risks and opportunities that could impact the OH&S objectives or the effectiveness of the management system. This requires a thorough understanding of the organization’s operations, legal obligations, and the needs and expectations of workers and other relevant interested parties. The planning process is not just about managing risks, but also about recognizing opportunities that can lead to improved OH&S performance, such as innovations in safety practices or increased worker engagement.
➤ To ensure these risks and opportunities are managed effectively, the organization must establish OH&S objectives that are aligned with its policy and overall strategic direction. These objectives should be measurable, practical, and aimed at eliminating hazards or reducing risks to acceptable levels. Planning is not complete without a clear roadmap: actions must be defined to achieve these objectives, including assigning responsibilities, allocating necessary resources, setting deadlines, and outlining how progress will be monitored and evaluated.
➤ The effectiveness of Clause 6 is realized when risk-based planning becomes a dynamic, ongoing process that is integrated into daily operations. Rather than reacting to incidents, the system anticipates potential threats and implements preventive measures. This ensures compliance with legal and other requirements while also fostering a culture of continuous improvement. Planning, therefore, acts as the backbone of the OH&S management system, aligning policy with action and creating the foundation for the subsequent “Do”, “Check”, and “Act” phases of the PDCA cycle..
DO (Clauses 7 & 8) #
“Implement the processes as planned.”
- Clause 7: Support
Provide necessary resources, competence, awareness, communication, and document control (7.5).
➤ In ISO 45001:2018, Clause 7—Support—is a vital component of the “DO” phase in the PDCA (Plan-Do-Check-Act) cycle. The statement “Ensures that implementation is possible and effective” highlights how Clause 7 provides the operational backbone that enables the execution of planned actions from Clause 6 and sustains the functioning of the OH&S Management System (OHSMS).
➤ To turn plans into action, an organization must ensure it has sufficient and appropriate resources, including personnel, equipment, infrastructure, technology, and financial support. Without these, even the best-formulated plans will not succeed. Just as important is ensuring competence—workers must have the necessary knowledge, skills, and experience to carry out their OH&S responsibilities effectively. This often includes training, certification, and continual learning initiatives.
➤ Awareness is another critical element. Employees at all levels need to understand the OH&S policy, their contribution to the system, and the implications of non-compliance. Awareness builds a culture of safety and personal responsibility, making the system more than just procedural—it becomes embedded in daily behavior.
➤ Effective communication—both internal and external—is required to ensure that OH&S information is shared, understood, and acted upon. This includes clear reporting channels for incidents and hazards, as well as transparent updates on OH&S performance and system changes. Communication must flow across all levels and functions to foster alignment and collaboration.
➤ Documented information (Clause 7.5) ensures that processes are clearly defined, accessible, and controlled. This includes maintaining accurate records, ensuring version control, and securing access to documents that guide and support OH&S operations. Reliable documentation underpins consistency, audit readiness, and informed decision-making.
➤ Altogether, Clause 7 guarantees that all necessary inputs are in place to transform planning into real, effective action. It equips the organization with the people, tools, and systems needed to operate the OHSMS successfully, fulfilling the “Do” phase of the PDCA cycle.
. - Clause 8: Operation
Operational planning & control (8.1) including procurement process, eliminating hazards, managing change, emergency preparedness, and response.
➤ In the context of ISO 45001:2018, Clause 8 – Operation represents the heart of the “DO” phase in the PDCA (Plan-Do-Check-Act) cycle. This emphasizes that this is the stage where all the planning, preparation, and resource allocation from previous clauses are transformed into real-world action.
➤ Clause 8 ensures that operational activities are carried out in a controlled and safe manner by implementing the risk controls identified during the planning phase. This involves establishing clear procedures, responsibilities, and criteria to manage occupational health and safety risks effectively. Through operational planning and control (Clause 8.1), organizations determine how work will be performed under safe conditions, including the use of protective equipment, maintenance schedules, and defined workflows that minimize exposure to hazards.
➤ A central focus of Clause 8 is the elimination of hazards and the reduction of OH&S risks. This might involve substituting dangerous materials, redesigning processes to reduce exposure, or implementing engineering and administrative controls. These measures reflect a proactive approach to risk management, ensuring safety is embedded into operational procedures rather than added as an afterthought.
➤ Another key component is management of change, which ensures that any new processes, technologies, or organizational changes are assessed for their impact on OH&S before implementation. This prevents the introduction of new risks and maintains system stability.
➤ Additionally, emergency preparedness and response under Clause 8 require organizations to identify potential emergency situations and prepare plans, conduct drills, and ensure that employees are trained to respond effectively. This reinforces the system’s resilience and capability to handle unexpected incidents while protecting people and the environment.
➤ By implementing Clause 8, organizations demonstrate their commitment to regulatory compliance and stakeholder safety & health. It is in this stage that the OH&S Management System comes to life—ensuring that all risk controls, operational processes, and legal obligations are actively managed, monitored, and enforced. This clause translates intent into consistent, safe action, forming the core of the “Do” component in the PDCA cycle.
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CHECK (Clause 9) #
“Monitor and measure processes and results against policies, objectives, and legal requirements.”
- Clause 9: Performance Evaluation
Includes monitoring, measurement, analysis, evaluation (9.1), internal audits (9.2), and management review (9.3).
➤ Clause 9 of ISO 45001:2018—Performance Evaluation—is the foundation of the “CHECK” phase in the PDCA (Plan-Do-Check-Act) cycle. The statement “Monitor and measure processes and results against policies, objectives, and legal requirements” reflects the organization’s responsibility to evaluate whether its Occupational Health and Safety Management System (OHSMS) is functioning as intended and delivering on its commitments.
➤ This clause requires organizations to systematically monitor, measure, analyze, and evaluate their OH&S performance. This means going beyond compliance checklists and actively collecting data on workplace incidents, near misses, unsafe behaviors, health outcomes, and exposure levels. The goal is to assess whether the controls and programs implemented under Clause 8 (Operation) are effective and whether OH&S objectives defined in Clause 6 (Planning) are being achieved. Monitoring must be planned and conducted using defined methods that are reliable, consistent, and aligned with the nature of the risk.
➤ Internal audits play a crucial role in this phase. They provide an independent and objective review of how well the OHSMS is being implemented, maintained, and followed. Audits help to uncover non-conformities, process weaknesses, or opportunities for improvement. Importantly, audits must be conducted regularly and by competent personnel who are impartial to the activities being audited.
➤ Management review, another key part of Clause 9, ensures that the highest levels of leadership remain engaged with OH&S performance. During these reviews, top management evaluates the adequacy, suitability, and effectiveness of the OHSMS using inputs such as audit results, incident trends, stakeholder feedback, and performance against objectives. This enables informed decision-making and ensures alignment with organizational goals.
➤ By thoroughly evaluating its performance, an organization can verify whether the system is meeting expectations, identify areas for correction or improvement, and prepare for the next phase of the cycle. The “Check” phase is therefore not just about looking back—it is a forward-looking step that provides the evidence base for continuous improvement and risk reduction in the “Act” phase..
ACT (Clause 10) #
“Take actions to continually improve performance.”
- Clause 10: Improvement
Address nonconformities, corrective actions (10.2), and pursue continual improvement of the OH&S system (10.3).
➤ In the context of ISO 45001:2018, Clause 10 – Improvement represents the essence of the “ACT” phase in the PDCA (Plan-Do-Check-Act) cycle. The statement “Take actions to continually improve performance” signifies a structured commitment by the organization to not only react to problems but to proactively enhance the effectiveness of the Occupational Health and Safety Management System (OHSMS).
➤ Clause 10 focuses first on the identification and correction of nonconformities. When deviations, incidents, or system failures occur—whether through internal audits, inspections, or worker reports—the organization is required to respond promptly. This includes investigating the root cause, evaluating similar risks, and implementing corrective actions that prevent recurrence. This process ensures that mistakes become opportunities for learning, not repeating.
➤ Beyond correction, Clause 10 emphasizes the need for continual improvement. This is not limited to fixing what went wrong but includes proactively seeking ways to enhance safety culture, system performance, and worker engagement. Improvement efforts may stem from analysis of performance trends, benchmarking, employee suggestions, new technology, or evolving legal and regulatory requirements. The standard encourages the use of insights gained through performance evaluations (Clause 9), operational learning (Clause 8), and feedback mechanisms to drive systemic changes.
➤ By acting on lessons learned and aligning corrective actions with strategic goals, organizations can refine their processes, reduce risk exposure, and elevate OH&S outcomes over time. The “ACT” phase ensures that the system is dynamic—adapting to change, learning from experience, and pursuing excellence in health and safety management.
➤ Thus, Clause 10 closes the loop of the PDCA cycle by transforming evaluation results into meaningful, lasting improvements that sustain the effectiveness and relevance of the OH&S management system.
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Why PDCA Is Important in ISO 45001 #
✔ Promotes systematic thinking
✔ Enables risk-based approach
✔ Drives continuous improvement
✔ Supports compliance with legal and stakeholder expectations
✔ Empowers worker involvement and safe workplace culture
Key References: #
- ISO 45001:2018 full standard interpretation: OSHISIS ISO 45001 Guide
- ISO official explanation of PDCA in ISO Management Systems:
ISO.org – High-Level Structure - Clause-by-clause training video (optional for class reference):
YouTube – ISO 45001 Explained