Quality & Quality Tools

By Prof N D Sadaphal

Assistant Professor

Sanjivani College of Engineering, Kopargaon (Maharashtra State) 423601

Mechanical Engineering

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PROF N D SADAPHAL

MECHANICAL ENGINEERING DEPARTMENT

TE Mechanical Metrology & Quality Control

Quality & Quality Tools

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Quality?

Think about a product you bought. How can you define its quality?

Quality has been defined in a number of ways. When viewed from a consumers perspective, it means meeting or exceeding customer expectations.

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Dimensions of Quality

1. Performance: Will the product/service do the intended job?

2. Reliability: How often does the product/service fail?

3. Durability: How long does the product/service last?

4. Serviceability: How easy to repair the product / to solve the problems in service?

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Dimensions of Quality (Conti..)

5. Aesthetics: What does the product/service look/smell/sound/feel like?

6. Features: What does the product do/ service give?

7. Perceived Quality: What is the reputation of the company or its products/services?

8. Conformance to Standards: Is the product/service made exactly as the designer/standard

intended?

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What is Quality?

Definition of Quality: (by the quality gurus)

1. Quality is fitness for use (comfort) _ _ _ Juran

2. Quality is conformance to requirements_ _ _ Crosby

3. Quality is a predictable degree of uniformity and dependability,

at low cost and suited to the market_ _ _ Deming

4. Quality as the totality of features and characteristics of a product

or service that bear on its ability to satisfy given need.

_ _ _ ASQC

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What is Quality?

The degree to which a system, component, or process meets

(1) specified requirements, and

(2) customer or users needs or expectations IEEE

The totality of features and characteristics of a product or service that bears on its ability to satisfy stated or implied needs

ISO 8402

Degree to which a set of inherent characteristics fulfils requirements ISO 9000:2000

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Modern Importance of Quality Modern Importance of Quality 7

The first job we have is to turn out quality merchandise that consumers will buy and keep on buying. If we produce it efficiently and economically, we will earn a profit.-

William Cooper Procter.

Quality in service industries, government, health care, and education.

Current and future challenge: keep progress in quality management

alive.

Statistical Quality Control

Quality Assurance

Quality Management

Quality Characteristics Quality of Design- design which fulfils all requirement of Customer. (method of construction, material, safety, aesthetics/appearance, reliability etc)

Quality of Conformance- degree/extent to which product conforms its specification and drawing. ability to maintain specified quality design.(i.e. control of good quality)

Quality of Performance- how well manufactured product gives performance. (Quality design + Quality conformance) Availability- available things in product like life, maintainability and

reliability. Customer Service- service after product has been delivered. e.g. equipment installation, operational training, repair service, replacement of defective component etc.

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Cost of quality

Conformance Non-Conformance

Quality Costs

Appraisal cost Prevention cost External failure cost

Internal failure cost

Cost Report

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Cost of quality

Cost of quality = Cost of conformance + Cost of non-conformance

Cost of conformance is the cost of providing products or

services as per the required standards. This can be termed as good amount spent. (Prevention & Appraisal costs)

Cost of non-conformance is the failure cost associated with a process not being operated to the requirements. This can be termed as unnecessary amount spent.( Internal & External failure costs)

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Prevention Costs

Quality planning costs costs of developing and

implementing quality management program

Product-design costs costs of designing products

with quality characteristics Process costs costs expended to make

sure productive process conforms to quality specifications

Training costs costs of developing and

putting on quality training programs for employees

Information costs

costs of acquiring and maintaining data related to quality, and development of reports on quality performance

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Activities associated with Prevention costs

Market research Quality training programs. Contract review Design review Field trials Supplier evaluation Process capability review Design and manufacture of jigs and fixtures Preventive checks & maintenance

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Examples of prevention Cost

Equipment maintenance & repair

Fixture design and fabrication

Housekeeping

Market analysis Procedure writing Safety reviews Quality training Salesperson evaluation

and selection

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Appraisal Costs

Inspection and testing costs of testing and inspecting materials, parts, and

product at various stages and at the end of a process. Cost of Power & material required for testing.

Test equipment costs costs of maintaining equipment used in testing quality

characteristics of products (Calibration of instrument) Operator costs costs of time spent by operators to gather data for testing

product quality, to make equipment adjustments to maintain quality, and to stop work to assess quality

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Activities associated with Appraisal costs Proto type testing

Incoming material inspection

Process inspection/control

Final inspection

Laboratory testing / measurement

Quality audits.

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Audit

Document checking

Diagram checking

Equipment calibration

Final inspection

In-process inspection

Laboratory test

Personnel testing

Procedure testing

Prototype inspection

Receiving inspection

Shipping inspection

Examples of appraisal cost 16

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Internal Failure Costs Scrap costs costs of poor-quality products

that must be discarded. (fault of manufacturer/vendor)

Rework/repair costs costs of fixing defective products

to conform to quality specifications.

Extra payment made to operator to obtain required level of quality.

Process failure costs costs of determining why

production process is producing poor-quality products.

Process down-time costs costs of shutting down

productive process to fix problem.

Price-down grading costs costs of discounting poor-

quality productsthat is, selling products as seconds.

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External Failure Costs

Customer complaint costs costs of investigating and

satisfactorily responding to a customer complaint resulting from a poor-quality product.

Product return costs costs of handling and replacing poor-

quality products returned by customer.

Warranty claims costs costs of complying with product

warranties.

Product liability costs litigation costs resulting

from customer injury.

Lost sales costs costs incurred because

customers are dissatisfied with poor quality products and do not make additional purchases.

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1-10-100 Rule

$

$

$

$

$

$

$

$

$

$

1

10

100

Prevention

Correction/ appraisal (inspection/testing)

Failure

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The 1:10:100 rule

Rs.1 spent on prevention, will save Rs.10 spent on appraisal and Rs.100 on failure costs.

The earlier you detect and prevent a defect the more you

can save

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Cost of Quality Approach 21

Objective

Zero defects while minimizing all four quality cost

Relation Between cost/value Vs Quality 22

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Demings Cycle Deming Chain Reaction

Quality improvement is not a costly business option but a strategic imperative that is essential to business survival

Quality Cost Productivity

The Deming Chain Improve Quality Decrease Costs Improve Productivity Decrease Price Increase Market Stay in Business Provide More Jobs Return on Investment

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Demings Cycle

PDCA 24

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Plan to improve your operations first by finding out what things are going wrong (that is identify the problems faced), and come up with ideas for solving these problems.

Do changes designed to solve the problems on a small or experimental scale first. This minimizes disruption to routine activity while testing whether the changes will work or not.

Check whether the small scale or experimental changes are achieving the desired result or not.

Act to implement changes on a larger scale if the experiment is successful. This means making the changes a routine part of your activity. Also Act to involve other persons (other departments, suppliers, or customers) to implement them on a larger scale.

Demings 14 Principles.

1. Create Constancy of Purpose 2. Adopt A New Philosophy 3. Cease dependence On inspection For Quality 4. End lowest tender contracts 5. Improve Every Process Constantly / Forever 6. Institute Training 7. Adopt An Institute Leadership 8. Drive Out Fear 9. Break Barriers Between Staff Areas 10. Eliminate Exhortations And Targets 11. Eliminate Numerical Quotas 12. remove the barrier that rob Pride Of workmanship 13. Encourage For education & Self Improvement 14. Put everybody In The company To work For This

transformation

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Jurans Triology Approach

Joseph Juran is one of the Guru of Quality like Deming.

Juran defined quality as a Fitness for purpose

If product meets all the specifications, it may not fit for use.

Juran Trilogy consists of three basic quality-oriented processes:

quality planning

quality control

quality improvement.

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Quality planning

The role of quality planning is to design a process that will be able to meet established goals under operating conditions.

The subject of planning can be anything -- an engineering process for designing new products, a production process for making goods, or a service process for responding to customer requests.

Quality Planning involves Identifying customers.

Determining their needs.

Specifying the product features that satisfy those needs at minimum cost.

Designing the processes that can reliably produce those features.

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Quality control

The role of quality control is to operate and correct the process, so that it performs with optimal effectiveness.

Measure actual performance of product

Compare actual performance with goals set

Do the action on difference

The process of Quality Control involves: Establishing a measurement procedure

Measuring

Interpreting differences between measurement and goal.

Taking action to correct significant differences

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Quality improvement

The role of quality improvement is to take the process to higher levels of performance.

Assuming the process is under control, any waste that occurs must be inherent in the design of the process.

The object of quality improvement is to reduce waste to a much lower level.

The steps in Quality Improvement: Identify specific area for improvement. Diagnose the causes. Provide remedies. Prove that the remedies are effective under operating

conditions.

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Seven Quality Tools

Cause and Effect Diagrams Flow Charts Check-sheets Histograms Pareto Charts Control Charts Scatter Diagrams

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Understand the root causes of a problem BEFORE you put a

solution into place

Investigate the Root Causes

Cause and Effect Diagrams 32

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Cause & Effect Diagrams

Identify many different possible causes for a problem

See the relationships

between the many causes Helps determine which

data to collect

Why are cause and effect diagrams helpful?

Focused problem

Root cause Root cause

Root cause Root cause

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Cause and Effect Diagrams/Fish bone diagram/Ishikawa diagram

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Cause and Effect Diagrams/Fish bone diagram/Ishikawa diagram

Incorrect shipping

documents (Quality

Problem)

Manpower Materials

Methods Machine

Environment Keyboard sticks

Wrong source info

Wrong purchase order

Types Source info incorrect

Didnt follow proc.

Glare on display Temp.

No procedure

No communications

No training

Software problem

Corrupt data

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Makes customer wait

Absent receiving party

Working system of operators

Customer Operator

Absent

Out of office

Not at desk

Lunchtime

Too many phone calls

Absent

Not giving receiving partys coordinates

Complaining

Leaving a message

Lengthy talk

Does not know organization

well Takes too much time to explain

Does not understand customer

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Flow Charts

Benefits

Show what actually happens at each step in the process

Graphically display processes to identify redundancies.

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Start

Material Received

IS Material of

Satisfactory Quality?

Return to Supplier

Transfer to store

No

Yes

Stop

Raw Material Purchase

Store

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Check-sheets

Purpose:

Tool for collecting and organizing measured or counted data

Benefits:

Collect data in a systematic and organized manner

To determine source of problem

To facilitate classification of data

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Histograms

Purpose: To determine the spread or variation of a

set of data points in a graphical form

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Consider this simple example. Below shows the exam results collected from a 5 class of 50 individuals:

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Pareto Charts

Small number of failures are responsible for the bulk of quality costs, this phenomenon is called as Pareto Principle.

This pattern is also called the 80/20 rule and shows itself in many ways.

For example:

80% of sales are generated by 20% of customers.

80% of defects are caused by 20% of the problems.

80% of salary is given to 20% of workers.

20% - The Vital Few

or 80% - The Trivial/ Important Many

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Example of Pareto Chart

Daily average

Total number

A One operator (partner out of office) 14.3 172

B Receiving party not present 6.1 73

C No one present in the section receiving call 5.1 61

D Section and name of the party not given 1.6 19

E Inquiry about branch office locations 1.3 16

F Other reasons 0.8 10

29.2 351

Reasons why customers have to wait (12-day analysis with check sheet)

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100%

B C A D E F

Frequency Percentage

0%

100

200

300

Improvement

Significant few

Insignificant many

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Significant few

Insignificant many

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Control Charts

The control chart is a graph used to study how a process changes over time. Data are plotted in time order.

A control chart always has a central line for the average, an upper line for the upper control limit and a lower line for the lower control limit.

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Scatter Diagrams Purpose: Relationship between two characteristic value are plotted and analyze as

to whether a correlation exists between the two set of data.

To understand the behaviour of a process.

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This is a scatter plot showing the amount of sleep needed per day by age. As you can see, as you grow older, you need less sleep.

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Negative Correlation

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This scatter plots show the average income for adults based on the number of years of education completed.

Positive Correlation

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None Low High Perfect

Degrees of correlation:

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New Seven Quality Tools

Affinity Diagram : Grouping of the idea of Brainstorming.

Relation Diagram : Diagram of Why-why analysis.

Tree Diagram : For Systematically Pursuing the Best Strategies for Attaining an

Objective

Matrix Diagram : A matrix to express the strong-ness of relationship between two things.

Arrow Diagram : For Working Out Optimal Schedules and Controlling Them Effectively

Process Decision Program Chart (PDPC) : Used to plan various contingencies

Same to Flow chart

Matrix Data Analysis : Consists of a two-dimensional array to determine location and nature of problem

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Quality Circle

Formation of quality circle is becoming imperative in todays world where the customer's expectations keep changing and it become tougher day by day to get to the level of delighting the customer. Voluntary group of persons Meet on regular basis Work on similar tasks Share area of responsibility Solve problems related to work voluntarily meet regularly for about an hour every week to identify, analyze and resolve work related problems, leading to improvement, In their total performance and enrichment of their work life."

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Objective/Function

Change in attitude

Effective team work

Self development

Job satisfaction

Communication

Leadership development

Improved organizational culture

Promote individuals self-development

Create problem prevention attitudes.

Improve customer relations and service delivery

Encourage the flow of new ideas

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Benefits of quality Circles Increased in quality

self-development

team work

Improve over all company performance

and corporate image.

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Organization structure

Non Qc - Members

Members

Leader

Facilitator

Co-ordinator

Steering committee

Top Management

Element of quality circle A steering committee Coordinator Facilitator leader members

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Awards for Quality

National individual awards Rajiv Gandhi National Quality Award

IMC Ramakrishna Bajaj National Quality Award

Integrated Marketing Communication (IMC)

Malcolm Baldrige National Quality Award (MBNQA)

International awards European Quality Award

Canadian Quality Award

Australian Business Excellence Award

Deming Prize from Japan

Criteria- Leadership, Information and analysis, Strategic planning, Human resource, Business results, management, Customer and market focus

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