six sigma date: 05-10-2012training.bsnl.co.in/digital_library_source... · six sigma six sigma is a...

E1-E2 TELECOM FACTORY

SIX SIGMADate: 05-10-2012

CHAPTER-11

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Six Sigma

Six Sigma is a methodology for business management, which believes that all the criteria

making up a good product can be expressed in so many numbers. The system makes use

of process capability study as the primary tool to ensure that at least six standard

deviations are possible on either side of the ideal quality of the output. This is also called

the process mean or average.

With those deviations identified, it is possible for the industry management to ensure that

virtually none of the products will be below standard quality. This is done simply by

taking measures to keep production within the standards dictated by the process mean.

The term "Six Sigma quality" is often used to describe well-controlled processes. The

company Motorola is most commonly associated with the term, after naming one of its

key initiatives "Six Sigma Quality."

The Six Sigma methodology can help a company achieve breakthrough improvement

through the concept of Six Sigma design. Sigma is a letter in the Greek alphabet and is

frequently used as a measure of process variability in statistics.

Six Sigma requires that processes operate such that the nearest engineering requirement is

at least plus or minus six sigma from the process mean, and a Six Sigma-capable process

produces work that is nearly error free.

Historical background

Six Sigma was originally developed as a set of practices designed to improve

manufacturing processes and eliminate defects, but its application was subsequently

extended to many other types of business processes as well. In Six Sigma, a defect is

defined as anything that could lead to customer dissatisfaction and / or does not meet

business set specifications.

The elements of the methodology were first formulated by Bill Smith at Motorola in

1986. Six Sigma was heavily inspired by six preceding decades of quality improvement

methodologies such as quality control, TQM, and Zero Defects, based on the work of

pioneers such as Shewhart, Deming, Juran, Ishikawa, Taguchi and others. Like its

predecessors, Six Sigma asserts that:

E1-E2 Telecom Factory Telecom Factory Rev date 05-10-2012


• Continuous efforts to achieve stable and predictable process results (i.e. reduce process

variation) are of vital importance to business success.

• Manufacturing and business processes have characteristics that can be measured,

analyzed, improved and controlled.

• Achieving sustained performance and quality improvement requires commitment from

the entire organization, particularly from top-level management.

The basics of Six Sigma

Apply the Six Sigma methodology in an organization means less variation in processes,

fewer defects, higher quality, a more efficient production cycle, and faster business

transactions. Six sigma delivers very visible business benefits faster, and the effects are

more lasting and far reaching than most of the other business improvement strategies.

One aspect of the Six Sigma methodology involves reducing the number of errors in a

process to within acceptable limits of 3.4 defects per million opportunities and

minimizing variation. When a process is repeated many times, the outcome will differ

slightly with each repetition. This is called variation. With variation comes the

opportunity for error. The Six Sigma methodology aims to reduce variation so that the

opportunity for error is reduced, thereby increasing quality and productivity.

In statistical terms, sigma represents the variation around the mean. The mean of a

process is the average outcome of a number of repetitions of that process. When depicted

graphically, the mean measurement and the variation in measurements around the mean

form what is known as the normal distribution, or the bell curve. Sigma is the measure of

the variation around the mean, and corresponds to the number of defects in the process.

'Long Term Yield'

(basically the percentage

of successful outputs or

operations) %

Defects Per

Million

Opportunities

(DPMO)

'Process

Sigma'

99.99966 3.4 6

99.98 233 5

99.4 6,210 4

93.3 66,807 3

69.1 308,538 2

30.9 691,462 1

One to Six sigma conversion table



"...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..."

How to Calculate DPMO

Many organizations find it useful to have information about defects or errors that have

occurred in the past. But what if they could predict the future likelihood of producing

defective products or processes?

The defects per million opportunities (DPMO) calculation is a forward-looking metric

that provides information on the mathematical possibility that an organization will

produce defective products or services. This measurement tool considers the various

ways an individual unit can be considered defective, which is a term that describes an

entire unit that fails to meet acceptance criteria. A unit may be defective if it contains one

or more defects. Instead of focusing on the resulting number of defective units, a DPMO

calculation uses information within a unit to measure the performance results of a

process.

A DPMO calculation consists of three elements

A defect is the measurable failure to meet a customer's requirement or

performance standard.

A unit is the final product or service – in other words, the item that is produced.

An opportunity is any measurable quality within a unit that can result in a

defective product or service.

Calculating DPMO

A DPMO calculation looks at opportunities for defects within units that result in products

or services that fail to meet customers' requirements and performance standards.



In a DPMO calculation, the number of defects is divided by the product of the total units

and opportunities per unit. This result is then multiplied by one million. This formula

calculates the numerical possibility that an individual unit will be defective.

By focusing on the opportunities for defects within the individual unit, the more subtle

DPMO metric helps you to better understand your organization's performance.

The defects per million opportunities (DPMO) calculation provide information on the

mathematical possibility that an organization will produce defective products or services.

A DPMO calculation consists of three elements: defects, units, and opportunities. To

perform the calculation, you divide the number of defects by the product of the total units

and the opportunities per unit, and this result is then multiplied by one million. This

formula calculates the numerical possibility that an individual unit will have at least one

defect.

Six Sigma Methodologies

Six Sigma focuses on more than just error reduction - Only when all employees adopt Six

Sigma principles are its benefits realized. A large part of Six Sigma is process

improvement - by improving a process, defects are reduced and quality improved, and the

organization realizes the benefits of the methodology.

DMAIC

1. During the define phase, managers define the context and process objective from

the customer's point of view & steps are:

Define Customers and Requirements (CTQs)

Develop Problem Statement, Goals and Benefits

Identify Champion, Process Owner and Team

Define Resources

Evaluate Key Organizational Support

Develop Project Plan and Milestones

Develop High Level Process Map

2. During the measure phase, managers measure and evaluate how a process is

currently performed to determine its current status & steps are:

Define Defect, Opportunity, Unit and Metrics

Detailed Process Map of Appropriate Areas

Develop Data Collection Plan

Validate the Measurement System

Collect the Data

Begin Developing Y=f(x) Relationship

Determine Process Capability and Sigma Baseline



3. During the analyze phase, managers analyze process problems to identify their

root causes, and to understand the cause and effect relationships that result in the

observed problems & steps are:

Define Performance Objectives

Identify Value/Non-Value Added Process Steps

Identify Sources of Variation

Determine Root Cause(s)

Determine Vital Few x's, Y=f(x) Relationship

4. During the improve phase, managers improve the process through planned

process modifications and specific project solutions & steps are:

Perform Design of Experiments

Develop Potential Solutions

Define Operating Tolerances of Potential System

Assess Failure Modes of Potential Solutions

Validate Potential Improvement by Pilot Studies

Correct/Re-Evaluate Potential Solution

5. During the control phase, managers control the new and improved process

through monitoring & steps are:

Define and Validate Monitoring and Control System

Develop Standards and Procedures

Implement Statistical Process Control

Determine Process Capability

Develop Transfer Plan, Handoff to Process Owner

Verify Benefits, Cost Savings/Avoidance, Profit Growth

Close Project, Finalize Documentation

Communicate to Business, Celebrate

DMADV or DFSS

The DMADV project methodology, also known as DFSS ("Design For Six Sigma"),

features five phases:

Define design goals that are consistent with customer demands and the enterprise

strategy.

Measure and identify CTQs (characteristics that are Critical to Quality), product

capabilities, production process capability, and risks.

Analyze to develop and design alternatives, create a high-level design and

evaluate design capability to select the best design.



Design details, optimize the design, and plan for design verification. This phase

may require simulations.

Verify the design, set up pilot runs, implement the production process and hand it

over to the process owner(s).

The benefits of Six Sigma

For a company to realize the benefits of Six Sigma, the Six Sigma methodology must be

applied to all processes in a unified manner. This prevents the changes made to one

process from having a negative impact on another related process.

Applying Six Sigma thinking to processes benefits an organization in several ways:

generating sustained success – Six Sigma is not just a one-off quick fix that is

applied to solve individual problems – any changes made during implementation

are permanently adopted by the organization, changing its structure for the better,

and ensuring that the environment of success becomes permanent.

setting a performance goal for all employees – Six Sigma provides a realistic

performance goal that is common across all processes and systems – the goal of

reducing errors to just 3.4 per million opportunities. This performance goal gives

employees a definite target to work toward.

enhancing product and service value to customers – The quality of products

and services is improved and, as a result, these services and products have

enhanced value to customers. Enhanced value is a great feature that allows

companies to capture larger sections of the market, increasing revenue.

accelerating the rate of process improvement within the organization – Six

Sigma facilitates rapid change and improvement in an organization, rather than

gradual incremental change. This means that the rate of improvement is

enormously increased in organizations applying Six Sigma methodologies, which

is a great benefit.

promoting learning – In a Six Sigma environment of rapid change, adapting to

change is important and employers should promote learning new skills. The

sharing of learned skills and knowledge between people and departments is also

important in achieving the common performance goal of Six Sigma. This "cross-

pollination" between different areas of an organization strengthens all

departments and processes involved.

executing strategic change to move the company forward – When

management decides that change is needed, Six Sigma is an excellent way of

bringing about the necessary changes to both the actual processes and the strategic



direction of the organization. Six Sigma places an organization in a position

where it is poised to embark and succeed on a new strategic path.

Roles and responsibility of team members of six sigma project

There are several roles & responsibility in six sigma

1. Champions - these are the business managers who support & encourage six sigma

activities within the business

Typical Responsibilities for a Champion or Sponsor

Strategic Oversight

Determine strategic direction of project

Define requirements for success

Resolve resource issues for the team

Conduct periodic progress reviews

Assist in solution implementation

Assist in team selection

Communicate with Black Belt

2. Black belts - these are the people who have full time jobs in running six sigma

projects

Typical Responsibilities for a Six Sigma Black Belt

Project Management

Define the project, scope, team etc.

Marshall resources

Set goals, timelines & milestones

Report-out/update stakeholders & executives

Task Management

Establish the team’s Lean Sigma Roadmap

Lead the implementation of Lean Sigma Tools

Manage team meetings (Facilitation)

Project Management of the team’s work

Track and report team progress

Team Management

Select/adjust team membership

Establish team norms (ground rules)

Counsel team members

Coach other Six Sigma Belts



Manage the team’s organizational interfaces

Ensure the team are trained & equipped for their work

3. Green belts - these are people who are trained but only work part time on six

sigma projects

Typical Responsibilities for a Six Sigma Green Belt

Project Management

Define the project, scope, team etc.

Marshall resources

Set goals, timelines & milestones


Task Management

Establish the team’s Lean Sigma Roadmap

Lead the implementation of Lean Sigma Tools

Manage team meetings (Facilitation)

Project Management of the team’s work

Track and report team progress

Team Management

Select/adjust team membership

Establish team norms (ground rules)

Counsel team members

Manage the team’s organizational interfaces

Ensure the team are trained & equipped for their work

4. Master black belts - these are the people who live & breathe six sigma, overseeing

& monitoring all project activity

Typical Responsibilities for an MBB

Identify & define the portfolio of projects required to support a

business strategy

Set Scope, Goals, Timelines & Milestones

Assign & marshal resources

Train & Mentor Green Belts & Black Belts

Facilitate Tollgates or check points for "belt" candidates


Establish an organizations Six Sigma strategy/roadmap

Lead the implementation of Six Sigma

There are also some other roles - orange & yellow belts, etc. These are additions to the

traditional roles and are not always agreed upon by six sigma practitioners.



Questions:

1. What do you mean by Six Sigma and its basics?

2. Comment on Historical background of Six Sigma?

3. Define five-phase DMAIC methodology?

4. How you will calculate DPMO?

5. Briefly explain the benefits of Six Sigma?

6. Write the roles & responsibility of team members in six sigma project?


six sigma date: 05-10-2012training.bsnl.co.in/digital_library_source... · six sigma six sigma is a...

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