Lean Six Sigma Methodology

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Lean Six Sigma Methodology

The Lean Six Sigma Methodology consists of five phases: Define, Measure, Analyse, Improve and Control. Whereas Lean Six Sigma consists of tools of both approaches, Lean and Six Sigma, the project management approach follows the Six Sigma phases – the DMAIC cycle.

Lean Six Sigma methodology DMAIC

The Engine within: DMAIC

In the following, read about the application of DMAIC in practice.

DEFINE – Define the Problem

The DEFINE phase lays the foundation for a successful project. Hence, the key to success is a project definition based on a real business problem and a description of the project objective and the people needed to solve the problem. Since each process serves one purpose – fulfilling the requirements of the process customer – the collection of the voice of the customer (VOC) and its translation plays an important role. Additionally, a high-level overview of the process (SIPOC) will align the understanding about the scope of the process and its process steps among all members of the project team.

Therefore, the principal task of Define is to establish a well thought-through project charter.

  1. Define problem and charter project
  2. Identify related process and scope project
  3. Determine process metrics (CTQs, Ys)

Hence, this project phase of the Lean Six Sigma methodology helps to “organise success”. Read more…

MEASURE – Gather Data about Problem and Potential Root Causes

The MEASURE phase determines potential root causes for the problem and ensures the data collection for problem and potential root causes in order to establish the actual process performance. This data will help in ANALYSE to distinguish between vital few and trivial many root causes – the most important prerequisite for IMPROVE.

Therefore, this project phase of the Lean Six Sigma methodology sets the data foundation for all following steps.

  1. Decide which variables to measure (Ys, Xs)
  2. Verify measurement system and sampling approach
  3. Collect data
  4. Determine baseline process capability

The principal task of MEASURE is the data collection. Read more…

ANALYSE – Identify Vital Few Root Causes (Xs) that Drive the Problem (Y)

The ANALYSE phase examines the in MEASURE selected potential root causes concerning their influence on the problem using the previously collected data.

In ANALYSE, two different approaches play their part. One approach uses tools for data analysis, whereas the other approach features tools for process analysis. Usually, both approaches are necessary to perform comprehensive root cause analysis. However, experience has shown that turn-around-time problems need process analysis tools, while defect analysis requires data analysis tools. The respective other approach supports the principle toolset.

This project phase of the Lean Six Sigma methodology determines the vital few root causes that drive the problem. This information is critical for finding effective solutions. The following tasks in “Analyse” introduce process and data analysis methods. Data analysis is done in two steps, the graphical analysis and the statistical analysis.

  1. Conduct Process Flow Analysis
  2. Conduct Data Analysis
  3. Analyse cause-effect relationships and verify/quantify important Xs

The key task of the ANALYSE phase is the identification of root causes for the problem. Read more…

IMPROVE – Develop Innovative Solutions to Vital Few Root Causes (Xs)

The IMPROVE phase includes the generation of solutions for the vital few root causes, their test and implementation. For these solutions, the effectiveness will be shown to ensure that process changes and sometimes necessary investments yield the intended results.

Therefore, this project phase of the Lean Six Sigma methodology delivers solutions for the problem with a well thought through implementation plan.

  1. Identify solutions addressing important Xs
  2. Minimize risks and implement solutions

Hence, the aim of this step is to generate ideas for solutions and to plan successful implementation. Read more…

CONTROL – Sustain the Gains Long-Term

Finally the CONTROL phase includes measures to ensuring the long-term effect of process changes implemented during IMPROVE.

  1. Standardise new process and implement control system
  2. Document learnings and close project

Hence, this project phase of the Lean Six Sigma methodology ensures sustainability of the results. Read more…


In conclusion, the Lean Six Sigma Methodology is one of the success factors of this approach and needs to be followed tightly if one expects outcome of a Lean Six Sigma project.