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MODULE 5: MANUFACTURING

QUALITY

OBJECTIVES

LECTURES NOTES

Quality

Quality Control Quality Assurance Quality Circle Benefits of Quality Control Quality and Reliability Total Quality System Management of Quality

TRANSPARENCIES

QUALITY.DOC ENTREPRENEURSHIP

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QUALITY

Objectives

Explain what is Quality

Discuss the three elements of Quality

Explain the importance of Quality Control, Assurance, and Circles

Brief explanation of the benefits of Quality Control

Discuss Quality and Reliability and Total Quality System

Brief discussion of Management of Quality


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Lectures Notes1

Quality2

Definition

Quality is conformance to requirements or specifications. (Crosby 1979)

Quality is fitness for use. (Juran 1974)

The quality of a product or service is the fitness of that product or servicefor meeting its intended used as required by the customers. (Hence)

Quality Characteristics

Quality Characteristic may be one or more elements which define the intendedquality level of a product or service. Several grouping of these characteristics canbe formed in:

Structural characteristics include such elements as the lengthof a part, the weight of a can, the strength of a beam, the viscosity of

a fluid, and so on.

Sensory characteristics include the taste of good food, thesmell of a sweet fragrance, and the beauty of a model, amongothers.

Time-oriented characteristics include such measures as awarranty, reliability, and maintainability.

Ethical characteristics include honesty, courtesy, friendliness,and so on.

Variables and Attributes

1USE TRANSPARECIES SLIDESQUALITY.PPT2Mitra, Amitava, Fundamentals of Quality Control and Improvement, Macmillan Publishing

Company: 1993.


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Variables - characteristics that are measurable and areexpressed on a numerical scale.

Nonconformity- is a quality characteristic that does not meet itsstipulated specifications requirement.

Nonconforming - unit is one that has one or morenonconformities such that the unit is unable to meet the intendedstandards and is unable to function as required.

Attribute a quality characteristics if it can be classified as eitherconforming or nonconforming to a stipulated specificationsrequirement.

Defect

A defect is a departure of a quality characteristic from itsintended level or star that occurs with a severity sufficient to causean associated product or service no to satisfy intended normal orreasonably foreseeable usage requirements. ( ANSI/ASQCStandard A3 1987)

Standard or Specification

Specification: a set of conditions and requirements of specificand limited application, that provide a detailed description of theprocedure, process, material, product, or service for use primarily in

procurement and manufacturing. Standards may be referenced orincluded in a specification.

Standard: a prescribed set of conditions and requirements, ofgeneral or broad application, established by authority or agreement,to be satisfied by a material, product, process, procedure,convention, test method; and/or the physical, functional,performance, or conformance characteristics thereof. A physicalembodiment of a unit of measurement ( for example, an object suchas the standard kilogram or an apparatus such as the cesium beamclock).

Quality of Design

Quality of design deals with the stringent conditions that the product orservice must minimally possess in order to satisfy the requirements of the


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customer. It implies that the product or service must be signed to meet atleast minimally the needs of the consumer.

Quality of Conformance

Quality of conformance implies that the manufactured product or theservice rendered must meet the standards selected in the design phase.

Quality of Performance

Quality of performance is concerned with the operation of the productwhen actually put to use or the service when performed and measures thedegree to which it satisfies the consumer.

The Three Aspects of Quality

Quality

Quality ofconformance

Quality of Quality ofdesign performanceQuality Control

Quality control may generally be defined as a system that is used to maintain adesired level of quality in a product or service.

This task may be achieved through different measured such as:


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planning design use of proper equipment and procedures inspection taking corrective action in a case a deviation is observedbetween the product, service, or process output and a specified

standard.

This general area may be divided into two main subareas:

Statistical Process Control involves the comparison of theoutput of a process or a service with a standard and the taking ofremedial actions in case of a discrepancy between the two. Itinvolves the determination of the ability of a process to produce aproduct that meets desired specifications or requirements.

Acceptance Sampling Plans is a plan that determines thenumber of items to sample and the acceptance criteria stipulated

conditions such as the risk of rejecting a good lot or accepting a badlot.

Quality Assurance

The objective of the quality assurance function is to have a formal system thatwill continually survey the effectiveness of the quality philosophy of the company.

Quality assurance: all those planned or systematic actions necessary toprovide confidence that a product or service will satisfy given needs.

Quality Circles

Quality circle is typically an informal group of people, which may consist ofoperators, supervisors, managers, and so on, who get together to seek improvedways of making the product or delivering the service.

A quality circle tries to overcome barriers that may exist within the prevailingorganizational structure so as to foster an open exchange of ideas.

The group members feel a sense of insolvent in the decision making process

and develop a positive attitude toward creating a better product or service.

Benefits of Quality Control

The advantages of a quality control system, however, become obvious in thelong run.

First, the improvement in the quality of products and services.


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Second, the system is continually evaluated and modified to meet thechanging needs of the customer.

Third, a quality control system improves productivity, which is one of thegoals of all organizations.

Fourth, such a system reduces costs in the long run.

Fifth, with improved productivity, the lead time on the production of partsand subassemblies is reduced, which may result in an improvement inmeeting customer due dates

Keeping the customers satisfied is a fundamental goal.

A company that adopts this philosophy and uses a quality control system to helpin meeting this objective is one that will be competitive for a long time.

Quality and Reliability

Reliabilityrefers to the ability of a product to function effectively over a certainperiod of time when in use by the consumer.

Achievement of desirable standards of reliability is obtained by careful analysisin the product design phase.

The product is typically over designed to more than meet the performancerequirements over a specified time frame.

Total Quality System

Quality System: the collective plans, activities, and events that are provided to

ensure that a product, process, or service will satisfy given needs.

Generic guidelines for quality system ( ANSI/ASQC Standard Z-1.15 1979)

Policy, planning, organization, and administration.

Product design assurance, specification development, and control.

Control of purchased materials and component parts.


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Production quality control.

User contact and field performance.

Corrective action.

Employee selection, training, and motivation.

Legal requirements - product liability and user safety.

Sampling and other statistical techniques.

Quality Improvement

Quality improvement is a neverending process, and efforts to reduce the

variability of a process and reduce the production of nonconforming items shouldcontinue forever.

Whereas process control deals with identification and elimination of specialcauses that force a system to go out of control, in order to bring the process to astate of statistical control, quality improvement relates to the detection andelimination of common causes.

Management of Quality

Management

functions

Product phase Action to be taken

Plan Proposal phase Develop quality policy Plan for quality Set up guidelines forsystem administration Consider productliability/user safety


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Organize

Staff

Direct

Control

Design/planning phase

Pre-production phase

Production phase

Production and postproduction phase

Develop anorganization structure Design assurance Design change control Develop productionquality planning

Select employee Train employee Motivate employee

Monitor purchasematerials quality Monitor processquality control Direct final inspection Directhandling/inspection

Obtain qualityinformation Get data on fieldperformance Take corrective action Conduct statisticalquality control Manage quality cost


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Quality 123