Over the years and even now, people stand unaware of the difference between Kaizen, Lean and Six Sigma. They might be using it frequently, but clueless about the name of the tool they have equipped and the difference between these three. To dive deeper into the topic about the difference between each of these devices, let’s have a general background about each of these three tools separately which will provide insight to the differences between each as well.
Kaizen means “Change for the better” which is synonymous with continuous improvement. It is the tool that refers to a constant process of development rather than an achieved goal. Kaizen is creative planning in mind, and it not explicitly applied to as a tool. It shows how gradually small things add up to the efficiency of the system and how system improves in a short span with adequate ability. The person adopting these tools needs to look individually at each case and develop an insight to solving those problems, however petty they might be. Masaaki Imai introduced this Japanese term in his book Kaizen, the key to Japan’s Competitive Success in 1986. It has occupied a pertinent position in present era for a more prolonged lifespan of a company and a better way to solve all issues. Many small changes contribute in bringing about substantial change in an organization over time, and it continues to do so. 3MUs permanently identified by Kaizen is Muda (means waste), Mura (means inconsistency) and Muri (means the burden on the capital, people, and machines). It tends to improve business from all of these three aspects, elimination of waste, inconsistent change and boosting efficiency. Moreover, it is a bottom-up approach (means bottom drives the program and activities to the top). The structure of its implementation usually has small group circles like QC circle, QIC, WIT. It uses QC 7 tools and new QC 7 tools.
Lean is another tool which only recognizes Muda; means the waste. Waste is all that junk which does not or cannot contribute towards the betterment of the organization anymore. This wreckage is recognized when they lack value for the customers. Lean manufacturing emerged over the century through many successful and unsuccessful attempts of Ford and Toyota companies in their automobiles. Hence Lean is more focused on eliminating all the factors that play the role of slag in the business and production, which don’t meet customer satisfaction and are not valued by them. Moreover, it is a top-down approach (means top drives the program and activities to the bottom). The structure of its implementation usually has Lean Teams which solve problems and direct the work. It uses Lean tools like 5S, Kanban, Andon, JIT, TPM, etc.
Six Sigma, on the contrary, recognizes only Mura; which is the inconsistency or variability of different factors in a business. It is a well disciplined and methodical approach for the elimination of defects in a company. It uses two methods known as DMAIC and DMADV, known for Define, Measure, Analyze, Improve, Control and Define, Measure, Analyze, Design, Verify, respectively and are based on the Plan – Do – Check – Act cycle of Deming. This Six Sigma strategy employs advanced statistical techniques like Pareto charts and causes analysis, to reach targeted values. Additionally, Carl Friedrich Gauss introduced the concept of the standard curve which laid down the roots of this strategy. However in 1920’s it was shown by Walter Shewhart that the three sigma deviations from the mean or average is the mark where a process requires correction. Later on, other terms for measurement standards added to Six Sigma factor like Cpk, Zero Defects, etc. but the name Six Sigma assigned by Bill Smith who was Motorola Engineer. This tool focuses more on the end product and digging out the primary purpose of the defects that took place inevitably. Moreover, it is a top-down approach (means top drives the program and activities to the bottom). The structure of its implementation usually has Black, Green or Yellow belts. Lean IT
Hence the difference between all three tools is prominent; it can conclude that all machines have pros and cons, but the best one is Kenzen.