BMM4733_Quality Engineering

Quality Engineering

Chapter 1 Introduction to

QualityMohamad Zairi bin Baharom

Faculty of Mechanical EngineeringUniversiti Malaysia Pahang

Mohamad Zairi bin BaharomFaculty of Mechanical Engineering

Universiti Malaysia Pahang

Learning Objectives

When you have completed this chapter you should be able to:

Define quality, quality control, statistical quality control, and total quality management.

Know the history of quality. Understand the responsibilities of the

functional areas and the CEO. Know the quality functions served by the

computer.

Definitions of Quality

What is Quality? Degree of excellence, or general

excellence (…has quality) Attribute or faculty (…Has many good

qualities) Relative nature, character, or property Quality is conformance to requirements

or specifications (Crosby 1979) Fitness for use (Juran 1988) Degree to which a set of inherent

characteristics fulfills requirements (ISO 9000-2000)

Dimensions of Quality

Transcendent definition: excellence Product-based definition: quantities of

product attributes User-based definition: fitness for

intended use Value-based definition: quality vs. price Manufacturing-based definition:

conformance to specifications

DIMENSION MEANING

Performance Primary product characteristics

Features Secondary characteristic

Conformance Meeting specifications or industry standards

Reliability Consistency of performance over time

Durability Useful life

Service Resolution of problems and complaints

Response Human-to-human interface

Aesthetics Sensory characteristics

Reputation Past performance and other intangibles

The Dimensions of Quality

Historical Review of Quality

Skilled craftsmanship during Middle Ages Industrial Revolution: rise of inspection and

separate quality departments Statistical methods at Bell System (1924) The American Society for Quality (1946) Deming (1950) Juran (1954 First Quality Control Circles (1960) 1980s

TQM Statistical Process Control, SPC Malcolm Baldrige National Quality Award Taguchi

ISO (1990) Via Internet (2000)

Responsibility for Quality

Customer

Service

Packaging andStorage

Inspectionand Test

ProductionProcessDesign

Procurement

DesignEngineering

Marketing

QualityProduct

OrService

Responsibility for Quality

Marketing Help to evaluate the level

of product quality that a customer wants, needs..

Design Engineering Translate the customer’s

requirements into operating characteristics, exact specifications, and appropriate tolerances

Procurement Responsible for procuring

quality materials and components

Responsibility for Quality

Process Design Develops processes and

procedures that will produce a

quality product/service

Production Produce quality products

and services

Inspection and Test Appraise the quality of

purchased and manufactured items and to report the results

Responsibility for Quality

Packaging and Storage Preserve and protect the

quality of the productService Fully realizing the

intended function of the product during its expected life

Chief Executive Officer

The highest-ranking executive officer within a company or corporation, who has responsibility for overall management of its day-to-day affairs under the supervision of the board of directors

Ultimate responsibility for quality

35% of the time is spent on quality

Quality performances

Computers & Quality Control

Benefits: Information is stored in the computer and

transmitted efficiently to remote terminals Information is provided to employee at

the same time the work assignment is given

Ability to quickly update or change the information

The probability of fewer errors Powerful tool to help in the improvement

of quality The use of computers in quality is as

effective as the people who create the total system

Computers & Quality Control

Quality functions needs:Data collectionData analysis and

reporting Statistical analysisProcess controlTest and inspectionSystem design

Computers & Quality Control

Data collection: The decision as to how much data to collect

and analyze is based on the reports to be issued, the processes to be controlled, the records to be retained, and the nature of the quality improvement program

Computers are well suited for the collection of data

Faster data transmission, fewer errors, and lower collection costs can be achieved

Multiple sources of data can be used Identifiers are necessary for data analysis,

report preparation, and record traceability

Computers & Quality Control

Data analysis and reporting: Quality info is stored in the computer for retrieval at

a future time, analyzed, reduced, and disseminated in the form of a report

The analysis, reduction, and reporting are programmed to occur automatically in the system

Data can be easily summarized Data can be analyzed as they are being accumulated

and corrective actions are taken in real time Analysis of data using tools such as: Pareto,

Histogram, Software programs (Excel), Charts are made easier

Computers & Quality Control

Statistical analysis: Use of Statistical packages The quality engineer can specify a particular

sequence of statistical calculation to use for a given set of conditions

Time is saved and the calculations are error-free

Benefits:No more time-consuming manual

calculationsOne-time problem Process control

Computers & Quality Control

Process control: Computer programs control the sequence of events

performed during a process cycle Keep the measurement and control of critical variables

on target with minimum variation and within acceptable control limits

Computer numerically controlled (CNC) machines, robots, and automatic storage and retrieval systems (ASRS)

Benefits:Constant product qualityMore uniform startup and shutdownHigh productivity (less employees)Safer operation for personnel & equipment

Computers & Quality Control

Test and Inspection: Automated test systems can be programmed to

perform a complete quality audit of a product

Disadvantage: High cost of the equipment

Advantages: Improve test quality Lower operating cost Better report preparation Improve precision Automatic calibration Malfunction diagnostics

Computers & Quality Control

System Design: The integration of the diverse quality

function with other activities requires an extremely sophisticated system design

Expert systems are computer programs that capture the knowledge of experts as a set of rules and relationships used for such applications as problem diagnosis

Quality Issue (Iphone 5)

When the new iPhone 5 started landing in people’s hands last month, it didn’t take long before forums started to fill with comments from disgruntled customers complaining that their handset was delivered with scuffs and scratches on its anodized aluminum back.

A shortage of iPhone 5 components is also proving to be a problem for the Cupertino company, contributing to manufacturing challenges. As a result, RBC Capital Markets analysts have reevaluated their iPhone 5 sales forecast for the December quarter, cutting it to 49 million units from 57 million.

Worries about supply appear to have been a contributory factor in Apple’s falling share price, with $60 billion wiped off the company’s market value since the handset’s launch. On Tuesday shares closed at $635.85, significantly down from the record $700+ value they reached only a couple of weeks ago.

Sales drop

Saahare les drop