Over the past few decades there have been a few models for process improvement. Some have used a seven-step problem solving process. Others have used an eight-step problem solving process. Six Sigma typically uses a five-phased approach – DEFINE, MEASURE, ANALYZE, IMPROVE, CONTROL (known as “DMAIC”). Dr. W. Edwards Deming used a four-step process, which is more of a cycle – PLAN, DO, CHECK, ACT for process improvement.
The idea in the PLAN step is to define the process to improve. The DO step is implementing the plan and measuring its performance. The team then takes those measurements to assess whether they are getting the desired results. This is known as the CHECK step. The ACT step follows. The team decides on changes that need to be made to improve the process; then, the whole cycle starts again.
Use: This continuous improvement cycle approach is still popular today – especially in Lean implementation. Both DMAIC and PDCA approaches are seeking the same thing – continuous, ongoing, relentless improvements. Some argue that one approach is better than the other. It is this author’s opinion that is better for the team to pick one approach and stick with it than to attempt to pick the best of various models. The ‘water gets muddy’ if it team tries to combine various methods. Don’t get hung up on Six Sigma having to follow the DMAIC model. If the team feels more comfortable with the PDCA approach, that’s fine. Later Deming changed the model to PDSA (PLAN, DO, STUDY, ACT) because he felt that the word ‘study’ was more descriptive than the word ‘check’.
