Six Sigma and Lean are globally-recognized methodologies designed to make manufacturing more efficient. These two well-established approaches have proven time and again that they make organizations more profitable. In fact, some of the world’s most successful manufacturers credit their achievements to Six Sigma Lean processes. But what are Six Sigma and Lean, how do they work together and–crucially–how can manufacturers get the most value from them?
Six Sigma and Lean are often used interchangeably, and it’s true that both are essentially continuous improvement methodologies designed to make organizations more efficient. But although Six Sigma and Lean work towards the same overall goal, they have quite different perspectives on what drives inefficiency, and therefore how to tackle it.
Six Sigma is a statistical approach to eliminating product defects and maintaining consistent standards. The focus is on minimizing variability in the manufacturing processes on the basis that variability increases the likelihood of defects. According to the methodology, traditional organizations have a sigma level of two or three–they accept up to around 300,000 defects per million ‘opportunities’. A sigma level of six means a mistake occurs just 3.4 times out of a million.
Lean, on the other hand, is a framework for removing inefficiencies, or ‘waste’. By making the most efficient use of labor, materials, machinery and time, Lean minimizes the resources used in production. Resources that don’t add value to the customer count as waste and this can include unnecessary transportation, excess inventory, or defective products. The goal is to create a culture of ongoing improvement, where organizations are continuously identifying and eradicating waste until they reach–in Lean terms–perfection.
Six Sigma and Lean processes both work towards the same fundamental goal: to create the most efficient system possible and eliminate waste. The difference is that they have different perspectives on the root cause of waste.
Where Six Sigma and Lean overlap is where it matters: the advantage they offer organizations.
Six Sigma and Lean employ different tools and techniques designed to uncover and address process failings. It means that while they have the same end goal, they have different ways of getting there–helping manufacturers identify different kinds of process deficiency or waste. Lean is a more bottom-up solution, encouraging those involved in processes to suggest improvements. Six Sigma is more top-down, requiring experts to collate and analyze data. Used together, Six Sigma and Lean processes offer different perspectives on how to improve production, leading to collaborative solutions that reflect both data and experience.
Both Six Sigma and Lean rely on accurate data about production processes. The latest digital manufacturing solutions built on the industrial internet of things (IIoT) mean companies have vast amounts of data at their fingertips, and the ability to visualize and analyze it. Manufacturers are better equipped to uncover process problems and bottlenecks, and to model potential solutions. Process automation and robotics help streamline production, speeding things up and reducing the margin for error. Augmented reality offers faster, more effective methods of training employees. The data and tools enabled by Industry 4.0 and the IIoT allow manufacturers to gain more advantage, more quickly from Six Sigma and Lean.
Six Sigma and Lean are recognized across industry as essential tools in the quest to make manufacturing more efficient. Combined together, Six Sigma and Lean processes offer greater scope for identifying error and waste, and driving process improvements. Taking advantage of the latest digital technologies amplifies the gain, making it easier and more effective than ever to embrace continuous improvement.