The Deming Cycle (PDCA): A Management Approach Forming the Basis of Continuous Improvement
“94 per cent of all failures are the result of the system, not of people.”
W. Edwards Deming
This statement is one of the most frequently quoted expressions in modern quality management theory.
One of the main reasons for his worldwide recognition was his ability to assist and transform large companies, and even entire nations, through his management skills. He was regarded as the most influential Western management guru in Japan. According to Deming, many problems experienced within an organisation stem not from the employees themselves, but from the systems in which they operate. When processes are not designed correctly, even the most competent teams cannot deliver the expected performance. Conversely, well-designed and continuously improved systems both reduce errors and support sustainable success.
This philosophy also forms the basis of the concept of continuous improvement, which underlies today’s management system standards such as ISO 9001, ISO 14001, ISO 45001, ISO/IEC 27001, ISO/IEC 20000-1, ISO/IEC 27701 and ISO/IEC 42001.
So, how did the PDCA (Plan-Do-Check-Act) approach, now used in almost all management systems, come about?
The Beginning of a Transformation
In 1950, Japan was striving to rebuild its industry in the wake of the Second World War. Just as important as rebuilding production capacity was the need to regain trust in quality. At that time, the phrase ‘Made in Japan’ was associated in the international market with low-quality, cheap products.
The Japan Union of Scientists and Engineers (JUSE) invited the American statistician and management consultant W. Edwards Deming to Japan. The training sessions delivered by Deming transformed not only quality control methods but also management philosophy. The concept of measuring processes, managing them based on data, and continuously improving them quickly became one of the fundamental operating principles of Japanese industry.
However, the foundations of PDCA had been laid before Deming’s time
The Origins of PDCA
The initial foundations of the PDCA approach are based on the statistical quality control work developed by Walter A. Shewhart, who worked at Bell Laboratories in the 1920s. Shewhart argued that it was necessary to monitor not only process results but also the variability arising throughout the process, and he addressed this through a cyclical approach.
Deming, however, built upon this approach and took it beyond the realm of quality control. He transformed the concept of continuous improvement into a management model that could be applied to production processes and organisations as a whole.
The PDCA approach, known worldwide today as the Deming Cycle, has become widespread as a result of this work. PDCA is a four-stage management model that facilitates the planning, implementation, evaluation and improvement of processes.
The model is not linear. Once the fourth step is completed, the process returns to the planning stage and the cycle continues indefinitely. In this way, organisations aim to achieve better results with each cycle, rather than simply maintaining their current performance.
- Plan
Every improvement initiative begins with asking the right questions.The aim of this stage is to collect reliable data that will enable an accurate analysis of the current situation.
In this context;
- Current process performance is analysed,
- the root causes of the problem are investigated,
- Methods such as the Pareto Analysis, Ishikawa (Fishbone) Diagram and the 5 Whys are utilised,
- Objectives are set in accordance with the SMART criteria,
- Resources, responsibilities and a timeline are established.
A good plan directly influences the success of subsequent stages.
- Do (Implement)
Once the plan has been drawn up, the solution is not implemented directly across the entire organisation.It is first tested in a controlled environment.
At this stage:
- pilot schemes are carried out,
- Employees are provided with the necessary training,
- The implementation process is documented in detail,
- Performance data is collected on a regular basis.
The aim is to identify potential risks at an early stage and to develop a solution where necessary.
- Check
One of the most critical stages of the PDCA cycle is the evaluation process.In this step, objective data is used to measure whether the implementation has actually delivered the intended outcome.
In this context;
- Performance indicators are analysed,
- planned targets are compared with actual results,
- process performance is assessed using statistical methods,
- successful practices and areas requiring improvement are identified, and the findings are recorded.
The fact that Deming chose to use the term ‘Study’ rather than ‘Check’ in later years also demonstrates that this stage is not merely about checking but aims to learn from the results.
- Act (Take Action)
The final stage is where the results obtained are incorporated into the organisation.
- If the expected results have been achieved, the new practice is incorporated into standard processes and rolled out in a controlled manner.
- If the expected performance has not been achieved, the practice is reassessed, the necessary corrections are made, and the process returns to the planning stage.
Where is PDCA Used Today?
The PDCA approach is not exclusive to the manufacturing sector. Today, it is used in many different sectors to improve processes.
- Manufacturing: Improving process performance, Kaizen practices and lean manufacturing.
- Healthcare: Improving patient safety, reducing waiting times and resource management.
- Software: Agile development processes, sprint planning and continuous improvement initiatives.
- Service sector: Standardisation of service processes and enhancement of the customer experience.
- Public sector: Improving service quality and monitoring process performance.
How Has Digital Transformation Affected PDCA?
Digital technologies have made the implementation of the PDCA approach faster and more data-driven.
Nowadays;
- Sensors and IoT systems can automatically collect process data,
- Simulation software enables different scenarios to be tested prior to implementation,
- Real-time dashboards can monitor process performance instantly,
- and certain digital systems can automatically implement corrective actions in accordance with predefined rules.
These developments help organisations make decisions more quickly and manage improvement cycles more effectively.
How is PDCA Success Measured?
The effectiveness of PDCA implementations can be assessed through performance indicators such as the time taken to complete the cycle, the rate of achieving set targets, the level of employee participation in improvement activities, the cost savings achieved, improvements in process performance, and the financial benefits realised.
Continuous improvement forms the foundation of successful management systems. The PDCA approach, as outlined by Deming, is also the common working model for many international ISO standards today and helps organisations to systematically develop their processes.
CFE Academy supports organisations in complying with international requirements, improving their processes and implementing a culture of continuous improvement through the training and certification services it offers within the scope of ISO management system standards. For further information, please contact us at info@cfecert.co.uk.