Brief introduction to Lean 6 Sigma - the DMAIC concept

Jun 15, 2021

Many of you use this process improvement tool. For those who are not acquanted with it, here is a brief summary of the 5 steps of Lean 6-Sigma (DMAIC for short).

Six Sigma requires studying the process to be optimizedPer Wikipedia, Lean Six Sigma is a method that relies on a collaborative team effort to improve performance by systematically removing waste and reducing variation. It combines lean manufacturing and Six Sigma to eliminate the eight kinds of waste (muda): Defects, Over-production, Waiting, Non-utilized talent, Transportation, Inventory, Motion and Extra-processing (aka "DOWNTIME").

Lean Six Sigma uses the DMAIC phases similar to that of Six Sigma. The five phases include Define, Measure, Analyze, Improve, and Control. The five phases used in Lean Six Sigma are aimed to identify the root cause of inefficiencies and work with any process, product or service that has a large amount of data or measurable characteristics available. The DMAIC toolkit of Lean Six Sigma comprises all the Lean and Six Sigma tools.


Identify customer issues and requirements (Voice of Customer) and internal processes to address them. Develop a Problem Statement (what, where, when, how, why), quantify the opportunity, determine how progress will be measured, develop scope and project charter.


Develop a data collection plan, qualitative and quantitative, to determine how processes are doing. Develop performance standards and specifications. Use histograms, capability indices, box plot, run charts to organize the data.


Identify root causes, analyze discrete data and continuous data (chi-square tests, normality tests, t-tests, ANOVA tests, regression tests, etc.). Use Critical to Quality tools such as process mapping, cause and effect diagrams, pareto charts, FMEA (Failure Mode and Effects Analysis), statistical hypothesis, capability indices, etc.

Improve and Implement

Develop solutions and implementation plans, optimize process flow, standardize processes, perform Design of Experiments. Identify significant inputs and an improvement plan for those key inputs. Establish a "buy in" plan. Conduct cost/benefit analysis, quality benefit analysis, cost analysis and implementation costs.


Monitor and institutionalize process changes to make sure improvements will last. Develop a process control system which can include risk management, mistake proofing, SPC (Statistical Process Control), Calculate improvements and compare to objectives. Develop project closure summary and communicate to all stakeholders.


The benefits of Lean 6 Sigma include:

  • increased profit
  • simplified and standardized processes
  • decreased errors
  • improved employee performance and development
  • higher value perceived by customer.

For more assistance reducing waste and variation and improving your machine line's performance, contact your Valmet representative.

("Six Sigma" is a federally registered trademark of Motorola.)