MODULE 7

Quality Control Tools

The seven QC tools are the most popular tools, which are being used by quality conscious companies throughout the world for improvement of quality of products and processes.

A brief description of these tools is presented here:1. Cause-and-Effect Diagrams2. Flowcharts3. Checklists4. Control Charts5. Scatter Diagrams6. Pareto Analysis7. Histograms

7 Quality Control tools

Cause-and-Effect Diagrams

Called Fishbone Diagram or Ishikawa diagram Focused on solving identified quality problem

Flowcharts

Used to document the detailed steps in a process

Often the first step in Process Re-Engineering

Checklist

Simple data check-off sheet designed to identify type of quality problems at each work station; per shift, per machine, per operator

Control Charts

Important tool used in Statistical Process Control The UCL and LCL are calculated limits used to

show when process is in or out of control

Scatter Diagrams

A graph that shows how two variables are related to one another

Data can be used in a regression analysis to establish equation for the relationship

Pareto Analysis Technique that displays the degree of importance for

each element Named after the 19th century Italian economist Often called the 80-20 Rule Principle is that quality problems are the result of only

a few problems e.g. 80% of the problems caused by 20% of causes

Histograms A chart that shows the frequency distribution of observed values of

a variable like service time at a bank drive-up window Displays whether the distribution is symmetrical (normal) or

skewed

Six Sigma (6) Six Sigma is a business management strategy

originally developed by Motorola. As of 2009, it enjoys widespread application in

many sectors Six Sigma is a fact-based data driven structured

methodology that is used to create breakthrough improvements in business processes with a strong focus on customer needs.

It is used to solve tough business problems when the root cause of the problem or the solution is not known.

Six Sigma (6) A performance goal, representing 3.4 defects

for every million opportunities to make one. A series of tools and methods used to

improve or design products, processes, and/or services.

A statistical measure indicating the number of standard deviations within customer expectations.

A disciplined, fact-based approach to managing a business and its processes.

A means to promote greater awareness of customer needs, performance measurement, and business improvement.

Examples of the Sigma Scale

In a world at 3 sigma. . .

There are 964 U.S. flight cancellations per day.

The police make 7 false arrests every 4 minutes.

In Massachusetts, 5,390 newborns are dropped each year.

In one hour, 47,283 international long distance calls are accidentally disconnected.

In a world at 6 sigma. . .

1 U.S. flight is cancelled every 3 weeks.

There are fewer than 4 false arrests per month.

1 newborn is dropped every 4 years in Massachusetts.

It would take more than 2 years to see the same number of dropped international calls.

D M A I CD M A I C

Define

Measure

Analyze

Improve

Control

Improvement methodology

Six Sigma DMAIC DMAIC

Define the project goals and customer (internal and external) deliverables

Measure the process to determine current performance

Analyze and determine the root cause(s) of the defects

Improve the process by eliminating defects Control future process performance

When To Use DMAIC The DMAIC methodology, instead of the DMADV

methodology, should be used when a product or process is in existence at your company but is not meeting customer specification or is not performing adequately.

Six Sigma DMADV DMADV

Define the project goals and customer (internal and external) deliverables

Measure and determine customer needs and specifications

Analyze the process options to meet the customer needs Design (detailed) the process to meet the customer

needs Verify the design performance and ability to meet

customer needs When To Use DMADV

A product or process is not in existence at your company and one needs to be developed

The existing product or process exists and has been optimized (using either DMAIC or not) and still doesn't meet the level of customer specification or six sigma level

DMAIC Versus DMADV The Similarities of DMAIC and DMADV

Six Sigma methodologies used to drive defects to less than 3.4 per million opportunities.

Data intensive solution approaches. Intuition has no place in Six Sigma -- only cold, hard facts.

Implemented by Green Belts, Black Belts and Master Black Belts.

Ways to help meet the business/financial bottom-line numbers.

Implemented with the support of a champion and process owner

A quality circle is a volunteer group composed of workers who meet together to discuss workplace improvement, and make presentations to management with their ideas. Typical topics are improving safety, improving product design, and improvement in manufacturing.

Quality Circles

Quality Circles

Group of employees who meet regularly to solve problems

Quality Circles are small groups of people who do similar or related work and meet regularly to identify, analyse,and solve product-quality and production problems and to improve general operations.

Trained in planning, problem solving, and statistical methods

Often led by a facilitator Very effective when done properly

Volunteers

Set Rules and Priorities

Decisions made by Consensus

Use of organized approaches to Problem-Solving

All members of a Circle need to receive training

Members need to be empowered

Members need to have the support of Senior

Management

QC Characteristics

Organization and Planning

Benefits of Quality Circles

Improved communication Greater job satisfaction Improved morale Improved quality Cost savings

Organization 8-10 members

Same area ModeratorPresentation

Implementation Monitoring

Solution Problem results Problem analysis

Cause & effect Data collection &

analysis

Problem ID List alternatives

Consensus Brainstorming

Training Group processes Data collection

Problem analysis

The Quality Circle Process

An analysis tool that provides a systematic way of looking at effects and their respective causes

Developed by Dr. Kaoru Ishikawa of Japan in 1943 and is sometimes referred to as an Ishikawa Diagram or a Fishbone Diagram because of its shape

Cause and effect diagram

Basic Use of the CE Diagram

The CE Diagram is basically used to investigate a problem, exploring, identifying, and displaying the

possible causes.

Purpose of the CE Diagram

To identify the relationship between the effects in a given situation and all of the possible causes

To find problem sources/solutions