A lot of companies have been incorporating Lean into their plan of process improvement, many of these already use a Six Sigma processes and probably want to integrate both systems. For some the benefits of both, like the focus of Six Sigma on the quality of processes and the emphasis of Lean in turn-around time, will be perfect for projects planned to be not only fast when it comes to results, but also high impact in what wants to be accomplished. Many though, will find problems integrating Lean in an ongoing Six Sigma process, so it is important to be careful when doing so. It may bring more problems than advantages, as the introduction may cause instability or ripples if not managed with care.
Using a structured and organized approach, you will be able to combine both methods without problems. So now we will talk about a couple of tools that will help you merging Six Sigma and Lean, these tools and principles have been used and have proved to be successful when using both Lean and Six Sigma so take some notes so you can use them yourself.
Load balancing or Heijunka, the Japanese name for the tool, and it refers to a production system that provides a constant and consistent work flow. Incorporating this principle will help if during the Design phase the analysis shows that there is the possibility of having one or multiple bottlenecks in the process. Load balancing will help make bottlenecks easier to handle as it will introduce a pull in the process instead of letting operate on push. The next principle we will discuss, takt time, will help using load balancing and will help ensure it.
Takt can be translated to beat in German and in this context refers to the rate at which a project must be finished to fulfill the demands and deadlines put by the customers. In some processes like manufacturing, the as-is cycle time must be captured in the Six Sigma phase of Measure, then it has to be compared to the service level agreements. Having an over the tolerance mismatch it would be needed to make improvements to meet the requirements using a system like takt time.
Cause and Effect Diagram and 5 Whys
This method, also known as Ishikawa, will help during the analyze phase to identify the cause of a problem that may be difficult to find. Asking five times why and accompanying it with a cause and effect diagram will make the task much more manageable, it will also help identify the process dynamics and the areas that can be dealt with more easily.
This method also has a Japanese name, poka-yoke , and it will be helpful when trying to tune or improve some steps in the process or when designing a Define, Measure, Analyze, Design, Verify system altogether. An Ishikawa chart can help during the Analyze process and will point where the major problems are in the process.
Value Stream Mapping
A value stream map can help during the Analyze phase of a DMAIC project, it will help organize and use information more effectively. It will show the flow of information and materials and will categorize the activities in three different segments: value adding, non-value adding and value enabling. And important part of this process is the elimination of the non-value added activities in the process and each one of the steps of it and will help reduce the waiting time between different consecutive the steps. The process to follow with value enabling activities is similar to the initial one, you should categorize them again into value adding and non-value adding and then proceed to eliminate the non-value adding ones again. This will help processes made to reduce variation in projects aiming to do so. This tool is also a very popular and useful one, not only in Lean Six Sigma but also in Kaizen when being incorporated in the Analyze and Improve phases.
After that you should set some milestones that will help keep the process focused, remember to plan the process carefully and take into account all the things that may cause problems during the integration. These tools are really helpful but do not assure you a perfect system, if you do not have the experience and the knowledge necessary to apply it you can always look for help of professionals and black belts.
If you have doubts about what is Lean manufacturing you should check this website as it explains it in an amazing way. Also if you liked the idea of Lean or Six Sigma you can read and find more content about it in this blog, with content like are Kaizen and Six Sigma good together? That will give you information about other models that can work with Six Sigma.