660 likes | 801 Views
Explore the fundamental aspects of quality and operations management with Dr. David Raffo's insights. This comprehensive overview defines quality in products and services, detailing its dimensions such as performance, aesthetics, and reliability. Discover the costs associated with poor quality, including failure, appraisal, and prevention costs. Learn about quality management frameworks, including important certifications like ISO 9000, and tools for quality control such as charts and diagrams. Enhance your understanding of how effective quality management can drive business success and customer satisfaction.
E N D
BA339 Quality and Operations Management Dr. David Raffo Tel: 725-8508, Fax: 725-5850 Email: davidr@sba.pdx.edu
Customer Customer Requirements Marketing & Sales Product Design Planning Forecasting Capacity Schedule Process Design Distribution Whse & transport, by channel Order Entry Production Quality Control Materials Management Supply Chain Management, Purchasing, Inventory Control Overview of Operations Management Support from Accounting, Finance, Human Resources, Information Systems
Quality Management • What does the term quality mean? • Quality is the ability of a product or service to consistently meet or exceed customer expectations.
Dimensions of Quality • Performance - main characteristics of the product/service • Aesthetics - appearance, feel, smell, taste • Special features - extra characteristics • Conformance - how well product/service conforms to customer’s expectations • Safety - Risk of injury • Reliability - consistency of performance
Dimensions of Quality (Cont’d) • Durability - useful life of the product/service • Perceived Quality - indirect evaluation of quality (e.g. reputation) • Service after sale - handling of customer complaints or checking on customer satisfaction
Table 9-1 Examples of Quality Dimensions
Table 9-1 Examples of Quality Dimensions (Cont’d)
Determinants of Quality Ease of use Design Conform-ance to design Service
The Consequences of Poor Quality • Loss of business • Liability • Productivity • Costs
Costs of Quality • Failure Costs - costs incurred by defective parts/products or faulty services. • Internal Failure Costs • Costs incurred to fix problems that are detected before the product/service is delivered to the customer. • External Failure Costs • All costs incurred to fix problems that are detected after the product/service is delivered to the customer.
Costs of Quality (continued) • Appraisal Costs • All product and/or service inspection costs. • Prevention Costs • All TQ training, TQ planning, customer assessment, process control, and quality improvement costs to prevent defects from occurring
Table 9-6 Key Contributors to Quality Management
Quality Awards Baldrige Award Deming Prize
Table 9-7 Malcolm Baldrige National Quality Award • 1.0 Leadership (110 points) • 2.0 Strategic Planning (80 points) • 3.0 Customer and Market Focus (80 points) • 4.0 Information and Analysis (80 points) • 5.0 Human Resource Development and Management (100 Points) • 6.0 Process Management (100 points) • 7.0 Business Results (450 points) • TOTAL POINTS = 1000
The Deming Prize • Honoring W. Edwards Deming • Japan’s highly coveted award • Main focus on statistical quality control
Quality Certification • ISO 9000 • Set of international standards on quality management and Quality assurance, critical to international Business • ISO 9000 series standards, briefly, require firms to document their quality-control systems at every step (incoming raw materials, product design, in-process monitoring and so forth) so that they’ll be able to identify those areas that are causing quality problems and correct them.
Seven Basic Quality Tools • Check sheets • Flowcharts • Scatter diagrams • Histograms • Pareto analysis • Cause-and-effect diagrams • Run Diagrams • Control charts
Check Sheet Monday • Billing Errors • Wrong Account • Wrong Amount • A/R Errors • Wrong Account • Wrong Amount
Number of defects Offcenter Smeared print Missing label Other Loose Pareto Analysis 80% of the problems may be attributed to 20% of the causes.
Diameter Time (Hours) Run Chart
1020 UCL 1010 1000 990 LCL 980 970 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Figure11-9 Control Chart
1 2 3 4 Figure 10-9 Observations from Sample Distribution UCL LCL Sample number
Samplingdistribution Processdistribution Mean Figure 10-4 Sampling Distribution
Samplingdistribution Processdistribution Mean Lowercontrollimit Uppercontrollimit Figure 10-6 Control Limits Specification Limits
Control Chart Uses • Decision making tools • Provide timely information on recently produced parts. • Helps determine process capability • Problem solving tools • Help locate and investigate causes of questionable quality • Aid operator in monitoring process
Control Chart Uses • Aid in process design and improvement • Data from current process can be evaluated against design targets • Help study changes made to process (with skilled interpretation)
Common Measures • Manufacturing - length, height, viscosity, color, temperature, and velocity • Service - # of errors, # of incorrect trx., delivery times, checkout times, cycle time, • Software - effort, deliverable dates, # defects by type, etc.
Developing a Control Chart 1. Take 20-30 random samples of size n where n depends on type of control chart 2. For each sample calculate sample statistic such as X-bar, R or p. 3. Plot the sample statistics sequentially
Developing a Control Chart 4. Calculate grand means and control limits 5. Evaluate results and recalculate control limits if necessary.
Common Causes of Variation • Procedures not suited to requirements • Poor product design • Machines out of order • Machines not suited to requirements • Barriers that rob the worker of the right to do a good job and take pride in his or her work
Common Causes of Variation • Poor instruction and/or supervision of workers • Poor lighting • Incoming materials not suited to requirements • Vibration
Are You Out-of-Control? A process exhibits a lack of control if: • any single value falls outside of the control limits. • any two out of three consecutive points fall in one of the A zones or beyond on the same side of the centerline. • four out of five consecutive points fall in one of the B zones or beyond on the same side of the centerline. • eight or more consecutive points lie on one side of the centerline. [10/11; 12/14; 14/17; or 16/20]
Are You Out-of-Control? • eight or more consecutive points move upward in value or if eight or more consecutive points move downward in value. • there are an unusually small number of runs above or below the centerline (sawtooth pattern). • thirteen consecutive points within the C zone.
Control Chart for Attributes • p-Chart - Control chart used to monitor the proportion of defectives in a process • c-Chart - Control chart used to monitor the number of defects per unit
Table 10-3 Use of p-Charts • When observations can be placed into two categories. • Good or bad • Pass or fail • Operate or don’t operate • When the data consists of multiple samples of several observations each
Statistical Process Control • Variations and Control • Random variation: Natural variations in the output of process, created by countless minor factors • Assignable variation: A variation whose source can be identified