Plan-Do-Check-Act in the ISO 9001 Standard

What is the best way to view the ISO 9001 Quality Management System requirements in order to make the individual processes within your system more compatible with each other? Each individual process can be improved by applying a Plan-Do-Check-Act approach, but the overall system can also benefit by this philosophy. By looking at the separate processes as being linked in one large cycle for improvement, you can help focus the improvement of the individual processes toward one greater good for the company.

Where does Plan-Do-Check-Act come from?

Plan-Do-Check-Act (also called “PDCA”) is a cycle that was originated by Walter Shewhart and made popular by Edward Deming – two of the fathers of modern quality control. This concept is a cycle for implementing change which, when followed and repeated, would lead to repeated improvements in the process it was applied to. An example that we might all relate to would be when you choose a wireless carrier: you Plan to have no problems with dropped calls; the Do phase is when you start using the phone service; the Check phase is when you monitor the real performance and get some dropped calls; and the Act phase is when you decide what to do – e.g., accept the number of dropped calls, call the provider to try to correct the situation, or change wireless carrier.


This is a model for improvement that is sustained, rather than just a one-time quick fix, and it is for this reason that it is applied to the ISO 9001 standard. The ISO 9001 standard has, as a main goal, the continual improvement of the Quality Management System.

How Plan-Do-Check-Act is found in the ISO 9001 Standard Requirements

In the introduction to ISO 9001, there is an explanation of the Process Approach and how important this is to implementing a Quality Management System that is compliant with the ISO 9001 requirements. In addition to this, there is a note about the methodology know as “Plan-Do-Check-Act” being applied to all processes. It then shows a graphic, which shows a very rough overview of how the standard requirements fit within a PDCA cycle. Below I will describe how the cycle of improvement works within the QMS (with the ISO 9001 clause numbers in brackets).

Plan – Planning is one of the biggest parts of the QMS and starts with understanding the context of the organization and the needs of parties interested in the QMS (4.1 & 4.2), which is then used to define the scope of the QMS and the QMS processes (4.3 & 4.4). This is followed by the commitment of leadership in the company to drive the organization to a customer focus by defining the organizational roles and responsibilities and by establishing a quality policy to give the overall QMS a focus (5.1, 5.2 & 5.3). The next level of planning is to identify and address risks and opportunities of the QMS, including setting and planning for quality objectives and changes to support continual improvement (6.1, 6.2 & 6.3). The final level of planning is to identify and implement the support structure to allow you to carry out your plans. This includes resources (7.1), identifying competence (7.2), awareness (7.3), communication (7.4) and to set the processes for creation and control of documented information (7.5).

Do – Planning is useless unless the plan is carried out. Controls need to be identified for the QMS operations, product or service requirements need to be identified (8.2), designs developed (8.3), controls placed on externally provided processes, products and services (8.4). The process of producing the product or service needs to be carried out with control of product and service release (8.5 & 8.6), any non-conforming products or services need to be addressed (8.7). In short, the activities of creating and providing products or services to the customers need to be done.

Check – There are several requirements in the standard to check the processes of the Quality Management system to ensure they are functioning properly as they have been planned. There is a need to monitor, measure, analyze and evaluate the products or services to ensure they meet requirements, the processes used are adequate and effective, and customer satisfaction is being met (9.1). Internal Audit (9.2) of the processes is the key way to assess the effectiveness of the system. Further is the Management Review process (9.3), which reviews and assesses all of the monitored data to make changes and plans to address the issues.

Act – Action in this case involves the actions needed to address any issues found in the check step. Improvement (10.1 & 10.3) is the overall heading for these action steps (10.1) with the activities of addressing nonconformity and Corrective Actions (10.2) to eliminate the causes of actual or potential nonconformities as the first step in acting to improve the system.

Plan – As stated, this cycle starts again to ensure there are plans in place for further improvement. Findings during the Internal Audit in the “Check” phase may have led to corrective actions from the “Act” phase, which in turn will require changes in planning to meet the updated requirements in the next “Do” phase. The Management Review looks at the outcomes of Internal Audit, Corrective Actions and outputs resource plans to support any changes. Resources are assessed and increased, decreased or re-assigned as the business needs dictate. This leads into another round of Doing, and the cycle continues.

An example would be if your company planned to reduce scrap by 5% by making certain changes to a process, the changes were made and the process ran, checking of the process showed that you reduced the amount of scrap by 3%, and you acted to make further changes to improve. The next planning for this process might be to make further changes and reduce the scrap by a further 4% in the following year.

Use PDCA to focus your QMS toward improvement

The goal of a QMS is to work toward improvement for the company, because only through improvement will a company be able to compete in industries that are growing ever more competitive. By using the PDCA cycle you will help to focus the processes and objectives of the QMS toward this desired improvement, leading to savings in time and money that can be used to improve further. With improvement as the goal of the QMS, the betterment and persistence of the business is more certain.

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Advisera Mark Hammar
Mark Hammar
Mark Hammar is a Certified Manager of Quality / Organizational Excellence through the American Society for Quality and has been a Quality Professional since 1994. Mark has experience in auditing, improving processes, and writing procedures for Quality, Environmental, and Occupational Health & Safety Management Systems, and is certified as a Lead Auditor for ISO 9001, AS9100, and ISO 14001.