The Plan Do Check Act (PDCA) cycle was created by Walter Shewart. It was titled the Shewhart Learning and Improvement cycle. His aim was to combine management thinking with statistical analysis. The four continuous steps: Plan, Do, Check and Act draw upon the notion that constant evaluation of management practices,  as well as the willingness of management to adopt and disregard unsupported ideas are key practices for the evolution of a successful enterprise.

W Edwards Deming then suggested changing the acronym to PDSA: Plan Do Study Act. The concept was similar to Shewart, one based upon continuous evaluation (study) and improvement.

There are several problems with PDCA or PDSA. I cover them in more detail in the Problems with PDCA page here. While some may appear trivial, they can have strong cultural, personal and enterprise implications. I summarise them below, although I recommend following the above link to obtain a more detailed understanding. Better understanding leads to more intelligent improvement.

• It oversimplifies what is really needed to improve.
• There is no real way to have continuous improvement. By definition, continuous means without  interruption.
• Do and Act have the same meaning in English.
• Shewart assumed that management would act, not the ordinary worker.
• Plan has a limited range of meaning. It  was not intended to cover aspects such as creative or innovative thinking as well as many other possible activities and outcomes.
• PDCA has an inherent circular paradigm. It assumes that everything starts with Planning. I challenge you to Think about times you did not plan something. Did you take an action that was based upon thought but no planning? Was the outcome acceptable or unacceptable? Successful improvement is possible without planning but not possible without thinking.
• PDCA was meant to be applied for small continual improvements, not large transformational change.
• People are explicitly not mentioned in the PDCA cycle. But people are what make improvement work.

Having seen the benefits of simple to understand models such as PDCA and also seeing the problems with PDCA has led me to improve the concept, hence:  'Improved PDCA'.

This page and related PDCA pages are published under GNU  Free Document license provisions.