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Chapter 1 Introduction. Introduction. Using statistical methods to improve quality I dentifying trouble spots and their causes Predicting major problems Quality : Fitness for use Meeting the needs of the marketplace Dynamic nature Quality: Variability To reduce variability
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Introduction • Using statistical methods to improve quality • Identifying trouble spots and their causes • Predicting major problems • Quality:Fitness for use • Meeting the needs of the marketplace • Dynamic nature • Quality: Variability • To reduce variability • To hit the target
1.1 Quality and Productivity • Misconception: inverse relationship between productivity and quality • Reduction in non-conformities • Reduction in rework • Eliminating complexity in the workplace (late delivery…)
1.2 Quality Costs • Cost of Achieving Good Quality • Prevention costs • Quality planning costs • Product design costs • Process costs • Training costs • Information costs • Appraisal costs • Inspection and testing • Test equipment costs • Operator costs • Cost of Poor Quality • Internal failure costs • Scrap costs • Rework costs • Process failure costs (Diagnostic) • Process downtime costs • Price-downgrading costs • External failure costs • Customer complaint costs • Product return costs • Warranty claims costs • Product liability costs • Lost sales costs
$ Increasing Quality Quality Improvement and Quality Cost • Break-even charts Total Quality Cost Failure Cost Appraisal Cost Prevention Cost
1.2 Quality Costs • Other considerations: • Sales • Customers’ perceptions • Market competition
1.3 Need for Statistical Methods • Statistical techniques are needed: • To determine if abnormal variation has occurred • To determine changes in the values of process parameters • To identify factors that are influencing process characteristics
1.4 Early Use of Statistical Methods for Improving Quality • Contribution to WWII • American Society for Quality Control (ASQC), 1946 • American Society for Quality (ASQ), 1997 • Industrial Quality Control, first issue in July 1944 • Journal of Quality Technology • Quality Progress
1.5 Influential Quality Experts • Walter A. Shewhart (1891~1967) • Shewhart charts • W. Edwards Deming (1900~1993) • Japanese progress • 14 points for management • PDCA (Plan-Do-Check-Act) cycle • PDSA (Plan-Do-Study-Act) cycle
1.5 Influential Quality Experts • Walter A. Shewhart (1891~1967) • Shewhart charts • W. Edwards Deming (1900~1993) • Japanese progress • 14 points for management • PDCA (Plan-Do-Check-Act) cycle • PDSA (Plan-Do-Study-Act) cycle
Deming's 14 points for Management • Create a constancy of purpose toward product improvement to achieve long-term organizational goals. • Adopt a new philosophy of preventing poor-quality products instead of acceptable levels of poor quality as necessary to compete internationally. • Cease dependence on inspection by relying instead on statistical quality control to improve product and process design. • Work constantly to improve the system.
Deming's 14 points for Management • Break down barriers between departments, and promote cooperation and a team approach for working together. • Do not award business to suppliers solely the basis of price. • Drive out fear. • Eliminate numerical goals, targets, and slogans. • Eliminate work standards and substitute leadership. • Institute a program of training and education for all employees.
Deming's 14 points for Management • Institute modern training methods of quality improvement throughout the organization, from top management down, so that continuous improvement can occur. • Remove the barriers that make it difficult for employees to do their jobs. • Institute and practice modern methods of supervision. • Create a management climate that will facilitate the attainment of these objectives.
1.5 Influential Quality Experts • Joseph M. Juran (1904~2008) • Quality management • Juran’s Quality Control Handbook • Eugene L. Grant (1897~1996) • Teaching of SQC • Statistical Quality Control, 1946 • Harold F. Dodge (1893~1976) • Acceptance sampling • Consultant to the Secretary of War (WWII) • George E.P. Box (1919~ ) • Control charts and process control in tandem
SOFTWARE APPLICATIONS • Excel • MINITAB