Improvement Methodologies: PM, Six Sigma, DFSS, Lean – Choosing the Right One

Posted by on Jan 17, 2021 in Continuous Improvement, Design for Six Sigma, DFSS, DMADV, DMAIC Process, Efficiency, Goal Setting, IDOV, Lean, Project Selection Criteria, Six Sigma, VOC | 0 comments


Organizations have a variety of tools and methods available to improve their products, services, and processes.  Deciding on which methodology to use can often become confusing because management does not understand how these methodologies are separated or used.  In this article, I’ll try to alleviate some of this confusion by providing you some examples of when it is appropriate to use each of these methodologies.

Project Management:  Used When The Problem Solution Is Known

Project management is defined as leading the work of a team to achieve goals and meet success criteria at a specified time. The primary challenge of project management is to achieve all of the project goals within the given constraints.  There are five phases to this process:  conception and initiation, planning, execution, performance/monitoring, and project closure.  Some examples of where project management applies would be launching a new service, a marketing campaign, the development of a new product, or the rollout of a new organizational software program.

Some of the steps required in project management include:

  • Define the project goals; that is, what do you want to achieve?
  • Identify the team members.
  • Define the work
  • Develop a plan that contains the project scope and objectives
  • Delegate the different project tasks
  • Execute and monitor the plan

Design for Six Sigma:  Used When a Process, Product, or Service Does Not Currently Exist

Often, organizations realize a process, product, or service doesn’t currently exist, and they need to develop one.  The traditional DMAIC Six Sigma methodology (Define, Measure, Analyze, Improve, and Control) does not adequately cover this situation and is modified.  This became known as Design for Six Sigma or DFSS.  It is a methodology for designing processes, products, or services correctly from the start, so that variation and defects are minimized.

Although there are different DFSS methodologies, each can be used as long as their different nuances are fully understood.  Examples of these methodologies are:

    • Define
    • Measure
    • Analyze
    • Design
    • Verify
    • Define
    • Measure
    • Explore
    • Develop
    • Implement
  • IDOV
    • Identify
    • Design
    • Optimize
    • Validate

In each, the first step is to define or identify exactly what the customer wants or needs.  This is typically known as the “voice of the customer,” or VOC phase.  The next step is to translate those needs into a product, service, or process that will fulfill their requirements.  When the design is complete, there is usually some verification or validation required to ensure the new design adequately meets those requirements.

Traditional Six Sigma DMAIC:  Used to Improve Existing Products, Services, and Processes By Reducing Variation and Defects

Six Sigma was created in the mid-1980s by Motorola to improve existing products, services, and processes.  The traditional methodology incorporates a 5-phase process known as DMAIC, which stands for Define, Measure, Analyze, Improve, and Control.  It consists of numerous tools and techniques that help the practitioner navigate through the DMAIC process and satisfy each phase’s deliverables.  It is the de-facto methodology for improving processes due to its ease of understanding, logic, and completeness.

Examples of Six Sigma projects are:

  • Reduce billing rejections for a healthcare organization
  • Eliminate defects in the manufacturing of solar cells
  • Reduce IT system downtime for an accounting firm

Lean Methodology:  Used to Reduce Cycle Time and Eliminate Waste in Existing Processes

While Six Sigma focuses on reducing variation, Lean drives out non-value-added waste and promotes standardization and flow.  The eight forms of waste that Lean concentrates on are:

  • Transportation:  movement of material, products, and information in an organization
  • Inventory:  raw material, work-in-process (WIP), finished goods, spare parts, office supplies, etc.
  • Motion:  people movement, i.e., employees searching for material and items required to do their job
  • Waiting:  waiting for material, information, and resources required to do the task
  • Over Production:  providing more than the customer needs or sooner than they need it
  • Over Processing:  giving the customer something they don’t need or are unwilling to pay for
  • Defects:  defective products and services, scrap, etc.

Examples of Lean projects include:

  • Reducing the lead time of a manufactured product
  • Reducing raw material inventory
  • Reducing customer wait time in hospitals

The tools and techniques used in Lean are very diverse and have a wide range of applicability, not only in manufacturing but in services and all types of businesses.  The use of Lean tools and techniques provides an organization with the ability to make the workplace efficient and effective.


Hopefully, you can see that organizations have many options available to them for making improvements, and I think this is where the confusion lies.  Each of these methodologies requires different tools and skills.  Organizations must determine what their biggest opportunities are and select the methodology that best applies.  This should become part of the business strategy.  The next steps are to train the right employees and the correct number of employees to accomplish their goals.

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