Introduction to Quality Student Notes

8/3/2019 Introduction to Quality Student Notes

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Introduction to Quality

Quality fundamentals

Quality: In terms of an excellent product or services, that fulfills or exceeds out

expectations.

Expectations: Are based on the intended use and the selling price.

Eg: plain steel washer ~ chrome-plated steel washer (both are different grade and cost

+ intended use)

y If a product or service surpasses customer expectations we consider that quality

y It is a perception

y

As Quality = performance / expectations (=1 OK, < 1 bad, > 1 good)

According to ANSI /ASQC, quality is the totality of features and characteristics of a

product or service that bear on its ability to satisfy implied or stated needs.

Stated needs: Contract / something written.

Implied needs: Function of market & must be identified & defined.

Need involves:

o Safety

o Availability

o Maintainability

o Reliability

o Usability

o Environment

o Economics (price)

Needs change over time specifications need to be re-evaluated periodically.

Quality Control:

It is the use of techniques and activities to achieve, sustain and improve the

quality of a product or service.

It involves integrating the following related techniques and activities:

1. Specifications what is needed

2. Design of the product or services to meet the specifications

Translated into

specifications

measureable and

quantifiable.


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3. Production and installation to meet the full intent of the specifications

4. Inspection to determine conformance to specifications

5. Review of usage to provide information for revision of specifications, if needed.

Aim Continued improvement.

Statistical Quality Control (SQC): It is a branch of Quality control (QC). It is the

collection, analysis, and interpretation of data for use in quality control activities.

Following are two major parts of SQC:

o Statistical process control SPC

o Acceptance Sampling

Quality Assurance:All the planned or systematic actions necessary to provide adequate

confidence that a product or service will satisfy given requirements for quality is called

quality assurance.

It includes:

o quality parameters for continuous evaluation for adequacy &

effectiveness.

o Corrective measures

o Feedback initiated where necessary

QC & QA difference:

QC involved with the activities of specifications, design, production / installation,inspection & review of usage

Responsibility of the functional areas

QA Also involved with the above activities as well as the entire quality system.

Quality assurance versus quality control:

Quality control emphasizes testing of products to uncover defects, and reporting to

management who make the decision to allow or deny the release, whereas quality

assurance attempts to improve and stabilize production, and associated processes, toavoid, or at least minimize, issues that led to the defects in the first place.

To prevent mistakes from arising, several QA methodologies are used. However, QA

does not eliminate the need for QC: some product parameters are so critical that testing

is still essential. QC activities are treated as one of the overall QA processes.

Failure testing:


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A valuable process to perform on a whole consumer product is failure testing or stresstesting. In mechanical terms this is the operation of a product until it fails, often understresses such as increasing vibration, temperature, and humidity. This exposes manyunanticipated weaknesses in a product, and the data are used to drive engineering andmanufacturing process improvements. Often quite simple changes can dramatically

improve product service, such as changing to mold-resistant paint or adding lock-washer placement to the training for new assembly personnel.

Statistical control:

Many organizations use statistical process control to bring the organization to Six Sigmalevels of quality, in other words, so that the likelihood of an unexpected failure isconfined to six standard deviations on the normal distribution. This probability is lessthan four one-millionths. Items controlled often include clerical tasks such as order-entryas well as conventional manufacturing tasks.

Traditional statistical process controls in manufacturing operations usually proceed byrandomly sampling and testing a fraction of the output. Variances in critical tolerancesare continuously tracked and where necessary corrected before bad parts areproduced.

Total quality management

Invariably, the Quality of output is directly dependent upon that of the participatingconstituents, some of which are sustainably and effectively controlled while others arenot. The fluid state spells lack of Quality control, and the process(es) which are properlymanaged for Quality such that Quality is assured, pertain to Total Quality Management.

The major problem which leads to a decrease in sales was that the specifications didnot include the most important factor, What the specifications have to state in order tosatisfy the customer requirements?.

The major characteristics, ignored during the search to improve manufacture andoverall business performance were:

y Reliabilityy Maintainability

y Safetyy Strength

As the most important factor had been ignored, a few refinements had to be introduced:

1. Marketing had to carry out their work properly and define the customersspecifications.

2. Specifications had to be defined to conform to these requirements.


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3. Conformance to specifications i.e. drawings, standards and other relevantdocuments, were introduced during manufacturing, planning and control.

4. Management had to confirm all operators are equal to the work imposed on themand holidays, celebrations and disputes did not affect any of the quality levels.

5. Inspections and tests were carried out, and all components and materials, bought

in or otherwise, conformed to the specifications, and the measuring equipmentwas accurate, this is the responsibility of the QA/QC department.6. Any complaints received from the customers were satisfactorily dealt with in a

timely manner.7. Feedback from the user/customer is used to review designs.8. Consistent data recording and assessment and documentation integrity.9. Product and/or process change management and notification.

If the specification does not reflect the true quality requirements, the product's qualitycannot be guaranteed. For instance, the parameters for a pressure vessel should covernot only the material and dimensions but operating, environmental, safety, reliability and

maintainability requirements.

Responsibility for Quality:

Quality is not the responsibility of any one person or department, it is everyones job.

Quality Management System (QMS): is process based.

Process:

Set on steps / instructions to achieve / deliver the requirements using available

resources within the constraints of standards.

Process refers to business & production activities of an organization. It must be

effective, efficient, under control, and adaptable.

Customer defines the purpose of an organization and every process within.

Business process includes:

o Purchasing

o Engineering

o Accounting

o Marketing

Inputs to a process may be: output from a processMaterial Information


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Money Data

Information product/sData services

INPUT / OUTPUT process Model (TQM, 3rd Ed, Basterfield)

All processes have at least one owner one performing the activities

Frequently the processes will cross multiple organizational boundaries, and supporting

sub-processes will be owned by individuals with in each of the organizations.

Improvements: Five (5) ways to improve:

1. Reduce resources

2. Reduce errors

3. Meet or exceed expectations of downstream customers

4. Make process safer

5. Make the process more satisfying to the person doing it

INPUT

Material

Money

Information

Data, etc

PROCESS

People

Equipment

Method

Procedure

Environment

Materials

OUTPUT

Information

Data

Product

Services, etc

OUTCOMES

CONDITION

FEEDBACK


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Ultimate goal of QMS: Customer satisfaction by continuous improvements.

Approaches to improvement:

1. Jurans Trilogy for quality improvement: It is based on cost oriented

perspective. It has three components: Planning, control, and improvement. Itis based loosly on financial processes such as budgeting (planning), expense

measurement (control), and cost reduction (improvement).

2. Shewharts Plan-Do-Study-Act cycle (PDSA) approach to continuous

improvement which was further modified by Deming as Plan-Do-Check-Act

(PDCA) approach to continual improvement.

3. Kaizen approach [Japanese approach]: Managements role in continuously

encouraging and implementing small improvements involving everyone.

a. Making small incremental improvements to the individual and the

organization

b. Behavioral approach.

Evolution of Quality:

Inspection

Qualit Control

Quality Assurance

y Defect identification level / model

y Inspection production Model

y Sampling Production Model

Individual Product

measures &

control

+ company-wide

performance

measures & control

Quality Management

+ Process measures &

control

Improving Quality

Process Control Model


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Reference from ISO-9001

Documents

Introduction to Quality Student Notes