quality & quality tools
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Quality & Quality Tools
By Prof N D Sadaphal
Sanjivani College of Engineering, Kopargaon (Maharashtra State) 423601
PROF N D SADAPHAL
MECHANICAL ENGINEERING DEPARTMENT
TE Mechanical Metrology & Quality Control
Quality & Quality Tools
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.
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?
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
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
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
Degree to which a set of inherent characteristics fulfils requirements ISO 9000:2000
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
Statistical Quality Control
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.
Cost of quality
Appraisal cost Prevention cost External failure cost
Internal failure cost
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)
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
costs of acquiring and maintaining data related to quality, and development of reports on quality performance
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
Examples of prevention Cost
Equipment maintenance & repair
Fixture design and fabrication
Market analysis Procedure writing Safety reviews Quality training Salesperson evaluation
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
Activities associated with Appraisal costs Proto type testing
Incoming material inspection
Laboratory testing / measurement
Examples of appraisal cost 16
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.
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
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.
Correction/ appraisal (inspection/testing)
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
Cost of Quality Approach 21
Zero defects while minimizing all four quality cost
Relation Between cost/value Vs Quality 22
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
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
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:
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.
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
Interpreting differences between measurement and goal.
Taking action to correct significant differences
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
Seven Quality Tools
Cause and Effect Diagrams Flow Charts Check-sheets Histograms Pareto Charts Control Charts Scatter Diagrams
Understand the root causes of a problem BEFORE you put a
solution into place
Investigate the Root Causes
Cause and Effect Diagrams 32
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?
Root cause Root cause
Root cause Root cause
Cause and Effect Diagrams/Fish bone diagram/Ishikawa diagram
Cause and Effect Diagrams/Fish bone diagram/Ishikawa diagram
Environment Keyboard sticks
Wrong source info
Wrong purchase order
Types Source info incorrect
Didnt follow proc.
Glare on display Temp.
Makes customer wait
Absent receiving party
Working system of operators
Out of office
Not at desk
Too many phone calls
Not giving receiving partys coordinates
Leaving a message
Does not know organization
well Takes too much time to explain
Does not understand customer
Show what actually happens at each step in the process
Graphically display processes to identify redundancies.
IS Material of
Return to Supplier
Transfer to store
Raw Material Purchase
Tool for collecting and organizing measured or counted data
Collect data in a systematic and organized manner
To determine source of problem
To facilitate classification of data
Purpose: To determine the spread or variation of a
set of data points in a graphical form
Consider this simple example. Below shows the exam results collected from a 5 class of 50 individuals:
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.
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
Example of Pareto Chart
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
Reasons why customers have to wait (12-day analysis with check sheet)
B C A D E F
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.
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.
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.
This scatter plots show the average income for adults based on the number of years of education completed.
None Low High Perfect
Degrees of correlation:
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
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
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."
Change in attitude
Effective team work
Improved organizational culture
Promote individuals self-development
Create problem prevention attitudes.
Improve customer relations and service delivery
Encourage the flow of new ideas
Benefits of quality Circles Increased in quality
Improve over all company performance
and corporate image.
Non Qc - Members
Element of quality circle A steering committee Coordinator Facilitator leader members
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