Lean Six Sigma (LSS) brings improved productivity at a lower operating costs to a business. It is a combination of two well-known process improvement methodologies; Lean and Six Sigma. Lean Six Sigma combines key tools and concepts from Lean and Six Sigma to provide a synergistic improvement program to processes in all types organizations and businesses. Implementing Lean Six Sigma improves process throughput, waste reduction and output defect reduction.
“… using both Lean and Six Sigma methods can reduce lead times by up to 80%, reduce manufacturing overhead and quality costs by 20%, and improve delivery time to above 99%.”
-Michael L. George, Lean Six Sigma
In a typical LSS implementation, the Six Sigma DMAIC framework is used as the implementation framework. The first step is to Define the processes requiring improvements and the targets that needed to be achieved. A champion and a project team is established to implement the LSS in the processes identified for improvements. LSS tools such as KPIs, Project Charter, Gantt Charts, Kaizen, RACI, etc. are used in this stage.
Second step is to Measure the processes. At this stage a mix bag of Six Sigma and Lean tools are used to evaluate the value stream mapping and SIPOC/COPIS. The main focus in this stage is to collect accurate data on the process parameters. Control charts, fishbone diagram, pareto charts, etc are used to collect data on the processes.
Third step is to Analyze the data collected on the processes. At this stage the main focus is to understand the characteristics of the processes working together and identifying contributing causes of process variations, bottlenecks and process waste. At this stage the reference process capabilities and takt times are determined. Some of the LSS tools used are 5Whys, Gemba, Affinity Diagram, MSA/GRR, Hypothesis Testing, OEE, etc.
Fourth step is to Improve the processes. At this stage a mix bag of tools and concepts are used from Lean and Six Sigma depending on the type of processes and what are the type of input-output upstream and downstream process linkages exist. The focus in this stage is to implement process changes to the 4M-1E with the objective of making the process more effective and efficient that increases throughput, reduce process waste, improve part quality. A bespoke Process Improvement Toolbox is required. Some of the LSS tools used in this stage are 5S, TPM, Kanban, Heijunka, Hoshin Kanri, JIT, DOE, FMEA, Process Capability Study, etc.
Final step is to Control the processes for continual performance. At this stage various tools and concepts from Lean and Six Sigma are implemented into the processes to monitor and control Key Performance Indicators (KPIs). Some of the LSS tools and concepts that would be implemented into the processes are PokeYoke, Andon, Jidoka, Control Charts, Control Plans, etc.
A successful implementation of LSS must focus on the outcome that will be gained from the implementation. The primary goal and focus is that the overall implementation reduces operational cost and increases productivity. Effectiveness and efficiency of the processes improves.