There are many problem methodologies used for process improvement. We’ll look at discussions and articles from experts on the comparisons among some of the more well-known approaches. If an article has a summary comparison chart, we reproduce it. We finish with a short video on mathematician George Polya’s 4-step Problem Solving approach.

Approaches Mentioned:

  • PDCA
  • A3
  • 8D (Ford)
  • 4Q
  • General Motors
  • Toyota 8 Step
  • Generalized Problem Solving


Comparing PDCA, A3, DMAIC, and 8D


In a post titled “PDCA, A3, DMAIC, 8D/PSP – what are the differences?” author Thomas Liesener compares PDCA, DMAIC, A3, and 8D.

Here’s Thomas’s Comparison Chart.



You can access the post here.


Quality Improvement Methodologies for Continuous Improvement


In a paper titled “Quality improvement methodologies for continuous improvement of production processes and product quality and their evolution” authors Sahno Jevgeni and Eduard Shevtshenko discuss PDCA, 8D, Six Sigma DMAIC, and 4Q.

Here’s their summary chart which includes the evolution time frame.



Copy and paste the following link into your browser to access the paper.


Process Improvement Methodology Selection in Manufacturing


In an article titled “Process improvement methodology selection in manufacturing: A literature review perspective” authors Ahmed Baha Eddine Aichouni, Faizir Ramlie, and Haslaile Abdullah discuss PDCA, DMAIC, 8D, and 4Q.

Here’s their summary chart.



You can access the article here.


Organizational Culture Traits and Problem Solving for Lean Transformation 

In a paper titled “An Assessment of Organizational Culture Traits Impacting Problem Solving for Lean Transformation” authors Saket Fadnavisa, Amir Najarzadeha, and Fazleena Badurdeena include a comparison of the problem solving approaches of Ford, General Motors, Toyota, and General Problem Solving.

Here’s their comparison chart.


Copy and paste the following link into your browser to read the paper.


George Polya’s How to Solve It


Hungarian Mathematician George Polya published a 4-step approach to problem solving in 1945.

You can see an overview of the approach in this short video from Narrative Symphony.

You can watch the video here.



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