How to integrate lean manufacturing with Six Sigma using 5 approaches that help overcome obstacles.
Both Lean and Six Sigma are popular strategies that manufacturers implement for Continuous Improvement. Six Sigma focuses on process quality while Lean emphasizes turn-around. As with any Continuous Improvement concept, these approaches can be combined to optimize a process. However, for those companies that have an existing Six Sigma framework in place, integrating Lean can disrupt the structure and prove more detrimental than beneficial.
A structured approach to combining Lean with Six Sigma will help ensure success of such a merge. For this, it is wise to assess the principles of Lean to determine which will support Six Sigma and fit seamlessly into the structure. Here are five Lean tools that may be especially applicable:
Takt time is basically the rate at which a project needs to be completed to meet customer demand. In manufacturing, the Measure phase can capture the as-is cycle time, and then it can be compared with existing service level agreements in the Analyze phase. Any mismatches that exceed the tolerance would require improvements to match the cycle time with the Takt time.
Cause and Effect
There are two cause and effect strategies that can be incorporated: the Ishikawa Diagram and the 5 Whys. The Ishikawa cause-and-effect diagram is commonly used to prevent quality defects. The causes for imperfection are sources of variation. Causes are usually grouped into major categories, and they usually include:
- People – everyone involved in the process
- Methods – requirements and details of how the process is performed, like policies, procedures, rules, etc.
- Machines – any equipment needed to complete the job – including raw, marts, office supplies, and anything used to produce the final product.
- Measurements – data used to evaluate the quality of the process
- Environment – all conditions in which the process operates
The 5 Whys can substitute Ishikawa when there’s an absence of concrete statistical data.
Value Stream Mapping
This is useful in the Analyze phase of Define, Measure, Analyze, Improve and Control (DMAIC.) This map shows the flow of materials and information, categorizing activities into three segments: value enabling, value adding, and non-value adding. The overall purpose of this map is to identify non-value added activities in each step so they may be eliminated. Value-adding activities can be sub-classified into value and non-value adding activities with the same intent.
This is also referred to as poka-yoke, and it is used to tweak process steps as well as effectively design a new system with Define, Measure, Analyze, Design, Verify. During Analyze, an Ishikiwa chart and Pareto analysis can help identify issues hurting the as-is process. During Improve and Design, poka-yoke can be used to redesign or improve the system to avoid error-inducing scenarios and eliminate a major cause of errors.
This is what the Japanese term Heijunka and it refers to a system that is designed to have a more even and consistent workflow. If the Analyze phase points to bottlenecks in the process, Heijunka can then be incorporated in the Design phase.
In Lean Manufacturing, tools like the electric-powered tugger are used to eliminate non-value added process, reduce bottlenecks, increase safety, and increase productivity. The experts at Load Mover, Inc. understand Continuous Improvement as it relates to manufacturing. They developed battery-powered tugs with concepts like Lean in mind. For a demonstration or discussion about what electric tuggers do and how they add value, contact 952-767-1720 or email firstname.lastname@example.org.