The House of Lean Six Sigma – Room 4

In Part 1 of this series, we reviewed the foundational concepts of Allergan’s visualization of The House of Lean Six Sigma, covering both the Foundation and Roof of their house diagram.

In Part 2, we jumped into Room 1, where a problem and its cause are known. This room represents a ripe opportunity for immediate application of the Improve stage of the DMAIC (Define, Measure, Analyze, Improve, Control) methodology. 

In Part 3, we moved into Room 2, where a problem is known, but the cause is unknown. In this room, the Analyze phase of the Lean Six Sigma methodology takes precedence. 

In Part 4, we continued to Room 3, where a problem is suspected but unknown. In this room, the first two stages of the DMAIC process—Define and Measure—become crucial.  

And today, we conclude with Part 5, heading to Room 4, where a problem is both unknown and unrecognized. These methods and proactive data analysis and continuous improvement practices can help uncover hidden issues hindering process efficiency or product quality. Uncovering these unknown problems provides opportunities for future Lean Six Sigma projects to optimize and enhance business operations.

DMAIC – Define, Measure, Analyze, Improve, and Control

DMAIC is the more well-known and most-used Lean Six Sigma project method. DMAIC focuses on improving an existing process by incorporating the following phases:

  • Define: Define the problem, output to be improved, customers, and process associated with the problem.
  • Measure: Collect data from the process to establish a baseline for the improvements.
  • Analyze: Analyze the data to find the root causes of defects.
  • Improve: Develop, test, and implement solutions to improve the process.
  • Control: Implement process controls to sustain the improvements.

DMADV – Define, Measure, Analyze, Design, and Verify

DMADV is focused on the process of designing a new product, service, or process, incorporating the following phases:

  • Define: Define the process and design goals.
  • Measure: Measure and identify critical-to-quality characteristics of the product, service, or process. This includes risk and production capabilities. 
  • Analyze: Analyze the data to find the best design.
  • Design: Design and test the product, service, or process.
  • Verify: Ensure that the design output meets the design input requirements (verification) and that the designed product performs satisfactorily under real or simulated conditions of intended use (validation). 


Failure Modes and Effects Analysis (FMEA) is a proactive tool used in Lean Six Sigma to identify potential failure modes in a process, assess their impact and likelihood, and prioritize them for improvement. By systematically evaluating potential risks and their effects, FMEA helps teams anticipate and prevent problems, enhancing the reliability and safety of processes and products.


Hazard Analysis and Critical Control Points (HACCP) is a systematic approach to identifying, evaluating, and controlling food safety hazards. Although not exclusively a Lean Six Sigma tool, its principles of proactive risk management align well with the methodology. HACCP helps organizations in the food industry ensure the safety of their products, preventing defects and reducing waste.

PPA (Preliminary Process Analysis)

Preliminary Process Analysis (PPA) is an early step in Lean Six Sigma projects, aiming to gain a high-level understanding of the current process. It involves identifying process steps, outputs, and potential defects, giving the team a clear overview of the process before they delve into more detailed analysis. PPA sets the stage for effective problem-solving and process improvement.

TRIZ (The Theory of Inventive Problem Solving)

The Theory of Inventive Problem Solving (TRIZ) is a methodology for systematic problem-solving. While initially not part of Lean Six Sigma, it complements the methodology well with its structured and innovative approach to problem-solving. TRIZ provides tools and techniques for identifying and resolving contradictions, stimulating innovation and process improvement.

QFD (Quality Function Deployment)

Quality Function Deployment (QFD) is a structured approach to defining customer needs or requirements and translating them into specific plans to produce products to meet those needs. In Lean Six Sigma, QFD helps ensure the improvements are focused on areas that are important to customers, enhancing customer satisfaction and business success.

DFSS (Design for Six Sigma)

Design for Six Sigma (DFSS) is an approach used in Lean Six Sigma for designing or redesigning a product or process. Unlike traditional Six Sigma, which focuses on improving existing processes, DFSS focuses on designing or redesigning different processes, products, or services to achieve Six Sigma-level quality. This method helps organizations design efficient, reliable, and high-quality processes from the start.


While these tools are an integral part of a Six Sigma program, they can also be implemented as standalone quality improvement actions or as part of other process improvement initiatives.  

Process improvement is a way of life at Thurman Co.

In addition to an in-house culture that thrives on ownership and responsibility throughout our team, we help businesses manage projects to significantly impact their success and growth, which often includes analyzing and improving processes.

When you’re ready to put your project in the hands of a trusted professional organization, contact us to learn more about working together.

Discover more from Thurman Co

Subscribe now to keep reading and get access to the full archive.

Continue reading