Difference Between PDCA and PDSA 

Key Difference – PDCA vs PDSA
 

PDCA and PDSA are two widely utilized improvement techniques to bring about process improvements. These methods are known as Plan-Do-Check-Act (PDCA) and Plan-Do-Study-Act (PDSA) and are well suited for many improvement projects. PDSA is a development from PDCA and the key difference between PDCA and PDSA is that PDCA is a repetitive four stage model (Plan, Do, Check, Act) used to achieve continuous improvement in business process management while PDSA contains the repetitive stages of Plan, Do, Study and Act. Both concepts were introduced by Dr. Edward Deming.

CONTENTS
1. Overview and Key Difference
2. What is PDCA
3. What is PDSA
4. Side by Side Comparison – PDCA vs PDSA
5. Summary

What is PDCA?

PDCA is a repetitive four stage model (Plan, Do, Check, and Act) used to achieve continuous improvement in business process management and was introduced by Dr.Edward Deming in 1950. Stages in PDCA form the basis for TQM (Total Quality Management) and ISO 9001 quality standards. This model is widely and successfully implemented in many business areas including but not limited to production managements, supply chain management, project management and human resource management.

The following elements should be considered in each stage.

Plan

This is the beginning of the process and the decision makers should take necessary initiatives to understand the nature of the current inefficiencies in the process, and why the changes should be implemented. In this stage, it is also important to ask the questions such as what the best ways to bring about the change are and what are the costs and benefits of implementing this.

Do

This is the implementation stage of the planned improvements. The support of the employees who are affected by the change is vital, thus, they should first be clearly informed regarding the changes and why are being implemented. Following this, the changes can be implemented as planned. If any type of resistance from the employees developed even after proper communication, the decision makers should be able to implement suitable remedies.

Check

In the Check stage, the decision makers evaluate whether the intended outcome has been achieved. In order to ‘check’, the actual results have to be compared against the expected results.

Act

The procedure for Act stage depends on the findings in the Check stage. If the Check stage proved that the process improvements were achieved during the Do stage, then the company should proceed to continue to act upon the new processes.

What is PDSA?

PDSA is a process improvement cycle that contains the repetitive stages of Plan, Do, Study and Act. While the overall cycle of PDSA is useful when used in improvement processes, the Check stage was considered inadequate by many quality practitioners.  Check stage of the process was meant to simply measure the improvement and move forward to the ‘Act’ stage. Thus, in 1986, Deming decided to amend his description of PDCA to emphasize the importance of reflecting on the meaning of the metrics  that is being checked, and thus PDSA emerged by replacing the Check stage with ‘Study’ stage.

The logic behind the Study stage in PDSA is to eliminate the drawbacks in the Check stage in PDCA by emphasizing the importance of not just checking, but using that knowledge to better understand the process to which improvements have been made.  The Study stage goes beyond mere understanding whether the intended process improvements are been made, but carrying out a critical and analytical review of whether the process improved, and in what ways that it improved. This type of detailed analysis becomes important in understanding the actual improvements made. Plan, Do and Act stage in PDSA is similar to PDCA.

What is the difference between PDCA and PDSA?

PDCA vs PDSA
PDCA is a repetitive four stage model (Plan, Do, Check, and Act) used to achieve continuous improvement in business process management.	PDSA is a process improvement cycle that contains the repetitive stages of Plan, Do, Study and Act.
Origins
PDCA was introduced in 1950	PDSA was originated in 1986 as a more effective alternative to PDCA.
Effectiveness
PDCA is less effective due to the Check stage.	PDSA is considered more effective since its inclusion of Study stage which has analytical value.

Summary – PDCA vs PDSA

The difference between PDCA and PDSA is a minimal one; they both consist of the same 3 stages of Plan, Do and Act, but PDCA consist of the Check stage and PDSA consist of the Study stage. Thus, the main difference between PDCA and PDSA improvement models depends on a single stage. The objectives that are expected to be realised through both models is similar, with many companies around the world using them. Even though these are very simple models to understand, its implementation may be complicated depending on the process they are used for.

References
1.”The Deming Cycle (PDSA or PDCA).” (PDSA or PDCA). N.p., n.d. Web. 26 Apr. 2017.
2.”What is PDCA (plan-do-check-act)? – Definition from WhatIs.com.” WhatIs.com. N.p., n.d. Web. 26 Apr. 2017.
3.”The W. Edwards Deming Institute®.” The W. Edwards Deming Institute. N.p., n.d. Web. 26 Apr. 2017.