The PDCA cycle or Deming wheel: how and why to use it

The PDCA cycle, often referred to as the "Deming Wheel" in honor of W. Edwards Deming, is an iterative method for continuous process or product improvement. The acronym PDCA stands for Plan, Do, Check, and Act.

Origins of the PDCA cycle

The PDCA (Plan-Do-Check-Act) cycle is often associated with W. Edwards Deming, but its origins can be traced through several significant contributions in the field of quality and management.

1. Walter A. Shewhart: In the 1920s and 1930s, statistician Walter A. Shewhart, then at Bell Laboratories, developed concepts around statistical process control and introduced a preliminary version of the cycle, often referred to as the Plan-Do-See cycle. Shewhart is often considered the "father of statistical quality control".

2. W. Edwards Deming: Deming, who was a protégé of Shewhart, adopted and adapted these ideas. Although the cycle is often called the "Deming Cycle", he always acknowledged Shewhart for his original contribution. Deming introduced this cycle in Japan in the 1950s, where it became a central element of post-World War II reconstruction and quality improvement efforts. In Japan, it was named the "PDCA cycle" and is sometimes called the "Deming-Shewhart Cycle".

3. Adoption in Japan: After World War II, Japan sought to rebuild its industry. As part of this initiative, many experts, including Deming, were invited to give lectures and training. The PDCA cycle was embraced by Japanese companies and became a fundamental component of their continuous improvement efforts, especially within the Total Quality Management (TQM) movement.

Over the years, PDCA has been incorporated into many continuous improvement methodologies and frameworks, such as Six Sigma, Lean Management, and other quality management systems.

It's important to note that, although the PDCA cycle is often attributed to Deming, he always emphasized the importance of Shewhart's work and often preferred to call it the "Shewhart Cycle".

Steps of the PDCA cycle

The four steps of PDCA are:

1. Plan:

   • Identify a problem or an improvement opportunity.
   • Analyze the current situation.
   • Set specific objectives.
   • Propose solutions and prepare an action plan.

2. Do:

   • Implement the action plan on a small scale, in a controlled setting (like a trial or test).
   • Gather data to analyze the effects of the changes.

3. Check:

   • Analyze the collected data.
   • Compare the achieved results with the set objectives.
   • Identify deviations and the causes of these deviations.

4. Act:

   • If the objectives are met, standardize the changes and deploy on a larger scale.
   • If objectives are not met, understand why and return to the "Plan" step to refine or rethink the solution.

The PDCA cycle is designed to be continuously repeated for continuous improvements. By repeating this cycle, organizations can identify and fix issues, improve processes, and ensure that improvements are effective and sustainable.

For which types of problems is the PDCA cycle suitable?

The PDCA is particularly well-suited to the following situations and problems:

1. Recurring problems: When an issue recurs frequently and its underlying cause is not clearly identified, the PDCA is useful for diagnosing, addressing, and preventing the issue.

2. Problems requiring incremental improvements: For situations that benefit from continuous adjustments rather than major overhauls, PDCA offers a framework for iterative improvement.

3. Situations with quantifiable data: The PDCA works especially well when outcomes or impacts can be quantitatively measured. This allows for objective evaluation during the "Check" phase.

4. Situations requiring a structured approach: For organizations or teams that struggle with addressing issues in a systematic manner, PDCA offers a clear and structured framework.

5. Changing environments: In situations where the environment is constantly evolving, PDCA enables organizations to adapt swiftly, adjust their plans, and act accordingly.

6. Quality improvement projects: Given its origins in quality control, the PDCA is naturally suited to efforts aimed at improving the quality of processes or products.

Here are situations where the PDCA cycle might not be the best method:

1. Urgent problems requiring immediate action: In crisis situations where swift action is needed, the systematic methodology of PDCA might slow down decision-making.

2. Highly complex problems with many interdependent variables: Although PDCA can be combined with other tools to address complex issues, on its own, it might oversimplify some situations.

3. Situations requiring radical innovation: PDCA focuses on continuous improvement, which might limit the "outside-the-box" thinking necessary for major innovations.

In summary, PDCA is a versatile tool suitable for many situations, but it's not universal. It's essential to assess the context and nature of the problem before choosing the best method or approach.

Using PDCA in innovation

PDCA can be employed in innovation, especially when introducing a new product in a production environment or implementing a new production process/equipment. We aren't including the product or process development part, which generally employs more specific methods.
Here's how introducing new products or processes in production can be tackled.

1. Plan

• Analysis of current capabilities: Examine your current facilities, equipment, and staff skills to determine if any changes are needed to produce the new product or to accommodate the new process/equipment.

• Identification of needs: Based on the analysis, identify the requirements in terms of staff training, purchasing additional equipment, or modifications to the facilities.

• Resource planning: Create a detailed plan for acquiring the necessary resources, whether it's material, training, labor, or time.

• Defining success criteria: Set KPIs (key performance indicators) to measure the success of introducing the new product or process/equipment in production.

2. Do

• Implementation: Acquire the planned resources, train staff if necessary, and start producing the new product or implement the new process/equipment.

• Monitoring: During production, ensure you closely monitor operations, especially in the early stages, to quickly identify any issues.

3. Check

• Performance measurement: Use the KPIs established during the planning phase to measure the success of introducing the new product or process/equipment in production.

• Feedback collection: Gather feedback from production staff on potential problems, inefficiencies, or areas for improvement. They can often provide valuable insights as they are on the front lines.

4. Act

• Analysis and optimization: Based on measured performance and feedback received, identify areas for improvement or correction. This might include adjustments to machines, changes in workflow, or additional training sessions for staff.

• Standardization: Once the new product is efficiently produced or the new process/equipment is fully integrated and working well, document the procedures and train all relevant staff to ensure consistency and efficiency.

After this "Act" phase, the cycle can begin again to enable continuous improvement.

Main difference between PDCA and other problem-solving methods

The primary difference between PDCA and other problem-solving methods like DMAIC or 8D lies in two major aspects:

1. Level of detail and flexibility:

   • PDCA is a general, flexible framework that can be adapted to a myriad of situations. Its simplicity allows for rapid and reactive deployment.
   • On the other hand, DMAIC and 8D are more prescriptive methodologies with detailed steps, specifically designed to tackle and solve complex problems using specific tools and analyses.

2. Type of improvement:

   • PDCA is oriented towards incremental and continuous improvements, ideal for regular adjustments based on feedback and observations.
   • DMAIC and 8D, meanwhile, are often used for more radical transformations or to address specific and complex problems that require deep understanding and a structured solution to ensure lasting resolution.

Thus, while PDCA lends itself to regular adjustments and continuous improvements, DMAIC and 8D cater to more specific and complex challenges with a more rigid structure.