Lean Six Sigma: The Five Phases
Lean Six Sigma is an organizational framework that aims to consistently increase the speed and quality of processes so as to deliver what the customer wants with the greatest possible accuracy, the lowest possible costs and the greatest possible flexibility. It was in the latter part of the 1980s that it was first used by a multinational telecoms company based in the U.S. Lean Six Sigma was pioneered by a quality engineer named Bill Smith, whose main goal was to improve quality and measurement systems to avoid errors. This was a stage in the telecoms company’s history when error rates were through the roof, creating too much rework, scrap and redundant testing that did not sit well with customers.
The Lean Six Sigma approach focuses on the identification and elimination of factors that lead to variations in the process. Once the variation is removed, results can be accurately predicted every time. By creating a system that makes sure these predictable results do not go beyond a zone of customer acceptability, process errors can be removed.
But that was not the end for engineers in that telecoms company. From their experience, they knew that several process changes did not address the root cause of the issue and were thus ineffective. Additionally, the changes would not be reliable because operators would go right back to how they did it originally after a while. These exact issues soon led to the five phases of Lean Six Sigma.
In this initial phase, the limits for the process are laid down, along with customer expectations for the said process. The purpose is to ensure changes will only upgrade customer experience rather than degrade it.
This phase involves measuring the present performance of the product, service or process as a way to understand what is really happening, especially from the perspective of a customer. This step aims to make sure that the basis for analysis and solution are concrete and actual facts rather than theories or anecdotal data.
In this step, the source or sources of the variation are determined through analysis of the product or service using the derived measurements. This leads to the determination of the problem’s root cause and not merely the symptom.
This phase entails studying possible changes to the process, product or service as well as testing them. This helps guarantee that the target outcome is achieved and that variations are minimized, if not totally eradicated.
This phase consists of the application of changes, upgrade of supporting systems, and control – generally statistical process control – of the process, product, or service to ensure full and sustainable implementation and ensure timely identification of signs of declining performance.