Introduction to Six Sigma, in the way you want to know !

What is Six Sigma?

A method that delivers organizations to improve the capability of their business practices. This increase in performance and decrease in process variation lead to defect reduction and improvement in profits, employee morale, and quality of products or services. Six Sigma quality is a term generally used to indicate a process is well controlled (within process limits ±3s from the center line in a control chart, and requirements/tolerance limits ±6s from the center line).

Diverse definitions have been proposed for Six Sigma, but they all share some common threads:

Use of teams that are assigned well-defined projects that have direct impact on the organization’s bottom line.

Training in “statistical thinking” at all levels and providing key people with extensive training in advanced statistics and project management. These key people are designated “Black Belts.” Review the different Six Sigma belts, levels and roles.

Emphasis on the DMAIC approach to problem solving: define, measure, analyze, improve, and control.

A management environment that supports these initiatives as a business strategy.

Six Sigma has two key methodologies:

  • DMAIC: It refers to a data-driven quality strategy for improving processes. This methodology is used to improve an existing business process.
  • DMADV: It refers to a data-driven quality strategy for designing products & processes. This methodology is used to create new product designs or process designs in such a way that it results in a more predictable, mature and defect free performance.

There is one more methodology called DFSS – Design For Six Sigma. DFSS is a data-driven quality strategy for designing or redesigning a product or service from the ground up.

Sometimes a DMAIC project may turn into a DFSS project because the process in question requires complete redesign to bring about the desired degree of improvement.

DMAIC Methodology:

This methodology consists of the following five steps.

Define –> Measure –> Analyze –> Improve –>Control

  • Define: Define the problem or project goal that needs to be addressed.
  • Measure: Measure the problem and process from which it was produced.
  • Analyze: Analyze data and process to determine root causes of defects and opportunities.
  • Improve: Improve the process by finding solutions to fix, diminish, and prevent future problems.
  • Control: Implement, control, and sustain the improvements solutions to keep the process on the new course.

DMADV Methodology

This methodology consists of five steps:

Define –> Measure –> Analyze –> Design –>Verify

  • Define: Define the Problem or Project Goal that needs to be addressed.
  • Measure: Measure and determine customers needs and specifications.
  • Analyze: Analyze the process to meet the customer needs.
  • Design: Design a process that will meet customers needs.
  • Verify: Verify the design performance and ability to meet customer needs.

DFSS Methodology

DFSS is a separate and emerging discipline related to Six Sigma quality processes. This is a systematic methodology utilizing tools, training, and measurements to enable us to design products and processes that meet customer expectations and can be produced at Six Sigma Quality levels.

This methodology can have the following five steps.

Define –> Identify –> Design –> Optimize –>Verify

  • Define: Define what the customers want, or what they do not want.
  • Identify: Identify the customer and the project.
  • Design: Design a process that meets customers needs.
  • Optimize: Determine process capability and optimize the design.
  • Verify: Test, verify, and validate the design.

 Features of Six Sigma

  • Six Sigma’s aim is to eliminate waste and inefficiency, thereby increasing customer satisfaction by delivering what the customer is expecting.
  • Six Sigma follows a structured methodology, and has defined roles for the participants.
  • Six Sigma is a data driven methodology, and requires accurate data collection for the processes being analyzed.
  • Six Sigma is about putting results on Financial Statements.
  • Six Sigma is a business-driven, multi-dimensional structured approach for:
    • Improving Processes
    • Lowering Defects
    • Reducing process variability
    • Reducing costs
    • Increasing customer satisfaction
    • Increased profits

The word Sigma is a statistical term that measures how far a given process deviates from perfection.

The central idea behind Six Sigma: If you can measure how many “defects” you have in a process, you can systematically figure out how to eliminate them and get as close to “zero defects” as possible and specifically it means a failure rate of 3.4 parts per million or 99.9997% perfect.

Key Concepts of Six Sigma

At its core, Six Sigma revolves around a few key concepts.

  • Critical to Quality : Attributes most important to the customer.
  • Defect : Failing to deliver what the customer wants.
  • Process Capability : What your 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 : Designing to meet customer needs and process capability.

Our Customers Feel the Variance, Not the Mean. So Six Sigma focuses first on reducing process variation and then on improving the process capability.

Myths about Six Sigma

There are several myths and misunderstandings surrounding Six Sigma. Some of them few are given below:

  • Six Sigma is only concerned with reducing defects.
  • Six Sigma is a process for production or engineering.
  • Six Sigma cannot be applied to engineering activities.
  • Six Sigma uses difficult-to-understand statistics.
  • Six Sigma is just training.

Benefits of Six Sigma

Six Sigma offers six major benefits that attract companies:

  • Generates sustained success
  • Sets a performance goal for everyone
  • Enhances value to customers
  • Accelerates the rate of improvement
  • Promotes learning and cross-pollination
  • Executes strategic change

Origin of Six Sigma

  • Six Sigma originated at Motorola in the early 1980s, in response to achieving 10X reduction in product-failure levels in 5 years.
  • Engineer Bill Smith invented Six Sigma, but died of a heart attack in the Motorola cafeteria in 1993, never knowing the scope of the craze and controversy he had touched off.
  • Six Sigma is based on various quality management theories (e.g. Deming’s 14 point for management, Juran’s 10 steps on achieving quality).

There are three key elements of Six Sigma Process Improvement:

  • Customers
  • Processes
  • Employees

The Customers:

Customers define quality. They expect performance, reliability, competitive prices, on-time delivery, service, clear and correct transaction processing and more. This means it is important to provide what the customers need to gain customer delight.

The Processes:

Defining processes as well as defining their metrics and measures is the central aspect of Six Sigma.

In a business, the quality should be looked form the customer’s perspective and so we must look at a defined process from the outside-in.

By understanding the transaction lifecycle from the customer’s needs and processes, we can discover what they are seeing and feeling. This gives a chance to identify weak areas with in a process and then we can improve them.

The Employees

A company must involve all its employees in the Six Sigma program. Company must provide opportunities and incentives for employees to focus their talents and ability to satisfy customers.

It is important to Six Sigma that all the team members should have a well-defined role with measurable objectives.

Six Sigma Belts (remember karate belts ! 🙂 )

Six Sigma professionals exist at all level – each with a different role to play. While executions and roles may vary, here is a straightforward guide to who does what.

At the project level, there are black belts, master black belts, green belts, yellow belts and white belts. These people conduct projects and implement improvements

Level Description with Roles and Responsibilities
Executives Provide overall alignment by establishing the strategic focus of the Six Sigma program within the context of the organization’s culture and vision
Champions Translate the company’s vision, mission, goals and metrics to create an organizational deployment plan and identify individual projects. Identify resources and remove roadblocks
Master Black Belt (MBB) Trains and coaches Black Belts and Green Belts. Functions more at the Six Sigma program level by developing key metrics and the strategic direction. Acts as an organization’s Six Sigma technologist and internal consultant.
Black Belt (BB) Understands Six Sigma philosophies and principles, including the supporting systems and tools. Demonstrates team leadership and understands all aspects of the DMAIC model in accordance with Six Sigma principles. Leads problem-solving projects. Trains and coaches project teams.
Green Belt (GB) Supports a Six Sigma Black Belt by analyzing and solving quality problems and is involved in quality-improvement projects. Assists with data collection and analysis for Black Belt projects. Leads Green Belt projects or teams.
Yellow Belt (YB) Participates as a project team member. Reviews process improvements that support the project. Has a small role, interest, or need to develop foundational knowledge of Six Sigma, whether as an entry level employee or an executive champion.
White Belt (WB) Can work on local problem-solving teams that support overall projects, but may not be part of a Six Sigma project team. Understands basic Six Sigma concepts from an awareness perspective

Different views on the definition of Six Sigma:

Methodology— This view of Six Sigma recognizes the underlying and rigorous approach known as DMAIC (define, measure, analyze, improve and control). DMAIC defines the steps a Six Sigma practitioner is expected to follow, starting with identifying the problem and ending with the implementation of long-lasting solutions. While DMAIC is not the only Six Sigma methodology in use, it is certainly the most widely adopted and recognized.

Metrics – In simple terms, Six Sigma quality performance means 3.4 defects per million opportunities

Philosophy— The philosophical standpoint views all effort as processes that can be defined, measured, analyzed, improved and controlled. Processes require inputs (x) and produce outputs (y). If you control the inputs, you will control the outputs. This is commonly expressed as y = f(x).

Set of tools— The Six Sigma expert uses qualitative and quantitative techniques to drive process improvement. A few such tools include statistical process control (SPC), control charts, failure mode and effects analysis, and process mapping. Six Sigma professionals do not totally agree as to exactly which tools constitute the set.


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