Root cause essentials: Using the PDCA approach to support continuous improvement

The continuous improvement cycle is the ongoing effort to improve your products, services and processes. This should be embedded into every part of every business.  

Studies show that continuous improvement will increase productivity, profit, and customer satisfaction and create less waste. To understand quality, you must seek improvement—you must produce quality.  

The origins of the continuous improvement cycle  

In the 1930s, an American engineer, statistician, professor, author and consultant Dr. Edwards Deming became intrigued by using statistics to improve quality.  Deming received international acclaim for his work in Japan after WWII which helped boost the economy.   

Dr. Demining’s philosophy of quality was simple. Focus on improving quality—this will automatically reduce costs. But if you focus on reducing costs it will automatically reduce quality and increase the actual price.  

Dr. Deming pioneered the Plan, Do, Check, Act (PDCA) methodology and felt strongly that feedback from the process and customers should be evaluated against the firm’s goals.

There is never a wrong time to start using a continuous improvement process; it is a simple and effective approach for testing on a smaller scale. For example, you could use this method: 

• During the development of a new product or process 
• When trying to improve a service or product 
• If you continuously have failures  
• Before you implement changes  

The phases of PDCA  

Let’s take a deeper look at the four phases of PDCA:  

Plan 

During this first step, you plan for the change and identify improvement opportunities. The key is to make sure your team understands how your company defines quality and make sure your goals are measurable.  

You’ll also need to identify and define the problem and provide the history, current losses, and possible gains. Some good tools to use for planning include the control chart and gap analysis.  

Then you need to analyze the investigation of the characteristics of the problem and identify the risk. Helpful tools to use include a histogram or Pareto diagram.  

Your process analysis also belongs in this phase. What is the root cause? Tools to use include the Five Whys, cause and effect, flowchart and fishbone diagram.  

Finally, you can create a solid action plan. 

Do 

This step considers what you should do and how you should do it. This starts with small scale testing. You need to implement the change, identity and document every step. Keeping the changes within a small test group will help you understand the data better. 

You’ll then look at whether you achieve the desired outcome. A great tool for this is the failure modes and effects analysis (FMEA).  

Check 

This is where you’ll check everything and consider what was achieved. You’ll verify the results against the criteria you put in your plan.  Does it meet the desired outcome? If the outcome was not met, why? What was wrong and what was miscalculated? Then you’ll start the process over again.  

Helpful tools to use include the histogram or control chart.  

Act 

If your check was effective, then you’ll implement the standardized solution. It doesn’t stop there. You’ll track performance and the data over time, if it starts to slip, you go back and improve. You’ll start back at the plan phase.  

The act phase is both the final and the first stage of the next cycle.

Closing thoughts

Always look for ways to make it better. What else could be done? How can we make it better? There is always room for improvement. Remember, continuous improvement is gradual never-ending change. 

Resources about root cause analysis:

• Blog: 5 steps to performing an effective root cause analysis
• Podcast: Flipping CAPA on its head with prevention and understanding the true root cause
• On-demand webinar: Root cause analysis – Getting to the root of the issue and getting it right
• Blog: Uncovering the root cause and overcoming challenges along the way
• Blog: Root cause essentials: Unleash the power of your mind with mind mapping