5 Lean Tools and Principles that can be integrated with Six Sigma
Today, more and more organizations are trying to complement Lean initiatives with Six Sigma within their existing framework. Combination of time-focused Lean turnaround and Six Sigma which focuses on process quality is believed to be able to deliver results with a large impact and targets can be achieved quickly. But to take advantage of these advantages, companies must face one challenge: integrating Lean with Six Sigma without creating friction in the structure of any of the methods that have previously worked.
With a structured approach, it is possible to combine Lean with the Six Sigma methods that have been implemented previously, as experienced by various companies on the Fortune 10 list. There are several Lean tools and principles that can be integrated with Six Sigma, including:
Value Stream Mapping (VSM)
In the Analyze phase (in the DMAIC project), a value stream map can be made to describe the flow of material and information, and categorize activities into three segments:value enabling), add value (value adding), and does not add value (non-value adding). The focus of VSM is to identify and eliminate non-value added activities in each step of the process and reduce the lead time between each step. Activities value enabling cannot be completely removed from the system. These activities can be divided into subcategories, namely value adding and non-value adding activities. What must be removed is activity non-value adding. Such elimination will help compact the process and provide the advantage of reduced variation. The VSM tool can also be used as part of the Kaizen cycle, which is applied to the Analyze and Improve phases.
Takt is a German word meaning “beat”. Takt time or time takt is the average time required to complete a process to meet customer demands. For processes that involve cycle timesuch as manufacturing processes, cycle time can be found in the Measure phase. Then, in the Analyze phase, cycle time can be compared with service level agreement (SLAs) that exist. If the mismatch has exceeded the tolerance limit, repairs must be made to match cycle time with takt time in system.
Ishikawa Diagram (Causage Diagram / Fishbone) and 5 Whys
In the Analyze phase, the absence of proper statistical data will make it difficult to identify the root cause. In this scenario, use the 5 Whys tool, which is to ask “Why?” multiple times, combined with the utilization of cause-and-effect diagramming tools, can make the job of digging easier root cause or root cause. Too 5 Whys can also help discover process dynamics in areas that can be handled easily.
Heijunka (Load Equalization)
in Japanese, Heijunka means a production system designed in such a way that the flow of work can run consistently. These principles can be incorporated in the Design phase if root cause analysis carried out in the Analyze phase identifies bottlenecks in the process. Load equalization can be done to encourage pull system and prevent the process from running push and reduce bottleneck. Efforts to enforce load distribution in the system will also automatically reduce inventory.
Poka-yoke (Mistake Proofing)
Poka-yoke is a Japanese term that means “error-proof”. This tool can be used to adjust process steps and when designing new systems with DMADV (Define, Measure, Analyze, Design, Verify). The combination of Ishikawa diagrams and Pareto analysis can be used in the Analyze phase, to find the main issues that are interfering with the process. During the Improve and Design phases, the possibility of eliminating the root causes of errors can be explored by improving or redesigning the system to avoid errors from occurring.***
Adapted from: Isixsigma.com; Shubhajit Roy.