Monday, February 13, 2012

Facilitating a Process Mapping Team, Part 3: The Skinny on Lean Six Sigma (LSS)

This article is the third in a series about facilitating process mapping. The first presented the basics of setting up the team and planning key facilitation tasks. The second, Conducting a Process Maturity Assessment, defined the organization according to the type of processes being mapped and provided key questions to assess the organization's overall process maturity. 
This article will:
  • Describe the origin of sigma (σ).
  • Introduce the six concepts that comprise Six Sigma.
  • Explain why these tools are considered lean.
  • Discuss the philosophy, formula, and laws of Lean Six Sigma.


A brief history of Six Sigma and lean thinking will help you understand how LSS came about, and how selected Lean Six Sigma tools are used in process mapping.

Six Sigma Defined
Sigma (σ) is a letter from the Greek alphabet that is used in statistics to measure variability. In Six Sigma methodology, a company's performance is measured by the sigma level. Sigma levels are a measurement of error rates. Because it costs money to fix errors, savings from reducing errors can be transferred directly to the bottom line.

Six Sigma was developed in 1981 by Motorola to reduce defects. Six Sigma incorporated Total Quality Management (TQM) and Statistical Process Control (SPC), and extended from a manufacturing focus to other industries and processes. Motorola documented $16 billion in savings, inspiring other firms to adopt the model. In 1988, Motorola won the Malcolm Baldrige National Quality Award (MBNQA) for its Six Sigma program.

Six Sigma specifies exactly how management should set up a project to achieve the most effective process.

The Six Concepts of Six Sigma
  • Critical to Quality: Attributes most important to the customer
  • Defect: Failing to deliver what the customer wants
  • Process Capability: What the process can deliver
  • Variation: What the customer sees and feels
  • Stable Operations: Ensuring consistent, predictable processes to improve what the customer sees and feels
  • Design for Six Sigma (DFSS): Aiming to meet customer needs and process capability
Six Sigma is based on statistical thinking and strives for defect reduction, process improvement, and customer satisfaction. It assumes that everything is a process and that all processes have inherent vulnerability.

Six Sigma theory relies heavily on data to understand the variability and drive process improvement decisions. It's all about reducing errors, mistakes, or defects. The table below shows the Sigma levels.


Thinking Lean
A great resource on the origin of lean thinking is The Quality Toolbox by Nancy R. Tague. Lean thinking is the application of the lean manufacturing concept to service operations. It is distinct in that lean services are not concerned with the making of "hard" products. Six Sigma is data and statistics driven. Lean thinking takes into consideration other factors such as gut feelings and the voice of the customer. Once the two are combined into Lean Six Sigma (LSS) the focus shifts to using the simplest possible graphs and explanations when presenting the research and solutions.

Eliminating obvious and hidden wastes are the main concerns of lean thinking. Obvious waste includes wait time, over-production, transportation time, and transactions that must be repeated. Hidden wastes are activities that do not add to the value of the item or service: for example, excess processing which occurs when two employees perform duplicate tasks. LSS relies heavily on Value Stream Mapping (VSM) to identify areas of waste. In project management, VSM is similar to Critical Path analysis. VSM can use tools and symbols similar to process maps. The idea behind VSM is that the viewer can easily see where resources need to be allocated. LSS is concerned with process capability and relies heavily on Critical to Quality (CTQ), going so far to build in analyses for measuring the measurement systems. The ultimate goal is to stabilize processes and build predictability into them, because a consistent stable process is one that can be improved more easily.

LSS for Success
LSS is often considered a formula for success, the core philosophy of LSS:

Customer Satisfaction = Process Improvement Success

Lean Six Sigma: Practical Bodies of Knowledge, by Terra Vanzant Stern, is a valuable resource on the topic because of its in-depth look at key LSS terms and concepts.

The Five Laws
(Derived from a combination of the principles of Six Sigma and Lean Manufacturing)

Customer satisfaction is the highest indicator of process improvement success.

Law 0- The Law of Market: The foundation for the five laws is referred to as the Zeroth Law. It states that Customer Critical to Quality is the highest improvement priority, followed by Return on Investment (ROI).
Law 1- The Law of Flexibility: The overall success and productivity of a process is dependent upon the presence of cross-trained employees that can effectively handle a variety of situations.
Law 2- The Law of Focus: The focus of process improvement originates from the theory that 20% of the activities cause 80% of the processing delay. Management can greatly improve results by targeting their efforts on improving the most problematic activities first.
Law 3- The Law of Velocity: The velocity of a process is inversely proportional to the amount of Work in Progress (WIP). Keep things off the to-do list.
Law 4- The Law of Complexity: The complexity of a service or product offering adds more non-value, costs, and WIP than either poor quality (low Sigma) or slow speed (un-Lean). Keep it simple.

We'll wrap up here with the introduction of the seven core quality management tools of LSS (listed below). Blogging with Bliss will follow up with our next installment about the first of the seven core LSS quality management tools, the process map.

The Seven Core Lean Six Sigma Quality Management Tools
  • Process Map
  • Cause and Effect Diagram 
  • Pareto Chart
  • Histogram
  • Checksheets
  • Scatter Plot
  • Control Chart 

Our guest contributor, Stephen Mercer, is an organization and process consultant. Stephen has diverse experience in a wide variety of industries. His background includes ten years as a senior technical writer, skilled in collecting, analyzing, reworking, and disseminating information tailored to specific audiences, and software process improvement and methodologies (e.g., Capability Maturity Model; CISA designation).

1 comment:

  1. Hello and thanks!
    Great articles! Keep 'em coming!