Total Quality Management TQM and Statistical Process Control

Total Quality Management (TQM) and Statistical Process Control (SPC) 11/1/2020 1

TQM • Quality: a powerful competitive weapon • Importance evidenced by variety of industrial awards (e. g. , Baldrige Award, Deming Prize) • Complex and multifaceted concept • TQM is a continuous, organization-wide effort to total customer satisfaction and continuous process improvement. The underlying principle of TQM programs is to produce products of high quality in the first place, rather than depend on detecting defective products later through inspection. 11/1/2020 2

Alternative Quality Definitions? • Product-based definition - quality is a precise and measurable variable where differences in quality reflect differences in the quantity of some ingredient or attribute possessed by a product. Example: content of multivitamins • User-based definition - in terms of satisfying the consumers’ wants, needs and preferences. Example: brand name manufacturer versus generic drugs • Manufacturing-based definition - conformance to requirements, meeting specifications. Example: interior diameter of pipe • Value-based definition - in terms of costs and prices. Quality is value for the dollar spent • Elimination of variability 11/1/2020 3

Garvin’s “Dimensions of Quality” 1. Performance – product/service primary characteristics 2. Reliability – consistency of performance 3. Durability – length of useful life 4. Conformance to specifications 5. Aesthetics – appearance, feel, smell, taste 6. Special features - extras 7. Safety 8. After sale service 9. Perceptions – indirect evaluation of quality 11/1/2020 4

Costs of Quality 1. 2. 3. 4. Internal failure costs External failure costs Appraisal costs Prevention costs 11/1/2020 5

TQM “Gurus” 1. Shewhart: “grandfather of SPC, ” Shewhart cycle 2. Deming: 14 points; “father of quality control, ” known for: appreciation of a system, knowledge of variation, theory of knowledge, knowledge of psychology 3. Juran: Pareto principle; trilogy or cross-functional management approach comprised of quality planning, quality control, and quality improvement 4. Crosby: Quality is Free; “do it right the first time” 5. Feigenbaum: total quality control (systems view) 6. Ishikawa: process improvement tools such as fishbone diagram 11/1/2020 6

6 TQM Programs Elements 1. Top management Leadership and Commitment • • Mission statement Product design Process design Employees After-the-sale service quality Plan-Do-Study-Act (PDSA, Shewhart cycle or Deming wheel) Long-term commitment to continuous improvement (kaizen) 11/1/2020 7

6 TQM Programs Elements 2. Customer Focus a. Internal: employee empowerment, participation, and teamwork (1) Participative Management: employee empowerment, participation, and teamwork (2) Education, training, standardized thinking (3) Technology and tools (4) Quality Circles A decentralization of management responsibility; objectives of increased productivity and quality; direct employee involvement; generally, a group of 3 to 10 employees doing related work and meets at regular intervals; provide for substantial individual motivation; improve managerial decision-making b. External customers (1) Quality Function Deployment (QFD) (2) Conformance to specifications 11/1/2020 8

6 TQM Programs Elements 3. Product/Service Design a. Design quality as a corporate objective b. Manufacturability and conformance to specifications • • • Idea: design and build in quality rather than inspect it in; nonconformance is costly; simplicity Cpk: ratio of allowable process variability to actual variability (versus Cpratio) Practices: product standardization, fewer parts {where for n independent components, system reliability Rs = (R 1)(R 2)(Rn) }, robotics, vertical insertion, redundancies [where for a back-up component, Rs = R 1+{R 2*(1 -R 1)}], improved supplier relations, preventative maintenance, ISO 9000, etc. c. Quality Function Deployment (QFD) d. After sale service quality: distribution, installation, after-the-sale support 11/1/2020 9

6 TQM Programs Elements 4. Process Management a. Quality at the Source; empowered employees • Authority + Responsibility = Accountability • Authority is the power granted to individuals so that they can make final decisions to complete their assignments • Responsibility is the obligation incurred by individuals in their roles in the formal organization in order to effectively perform assignments. • Accountability is the state of being totally answerable for the satisfactory completion of a specific assignment. b. Organizing for quality control • New organizational structures and teams(matrix) • Elimination of bureaucracy (fewer mgt. levels) c. Managing for quality control • Increased span of control • Engaged employees: quality control training, quality circles, participative management 11/1/2020 10

6 TQM Programs Elements 5. Managing Supplier and Supply Chain Quality 6. Use of Quality Tools a. Variation caused by chance causes (random variation) and assignable causes b. Process Improvement Tools: attempt to reduce the causes of variation before it happens (1) Benchmarking (2) Brainstorming (3) Process Mapping (Flow charting) (4) Pareto Analysis and Histograms (5) Cause-and-Effect Diagrams (Fishbone Diagram) (6) Check Sheets (checklists) (7) Scatter Diagrams c. Statistical Process Control (SPC) Techniques: attempt to identify assignable causes of variation so that it eventually may be eliminated (1) Control charts (2) Acceptance plans 11/1/2020 11

Process Mapping (Flowcharting) Different shapes represent different types of process flow tasks, e. g. , rectangle represents a task while triangle represents assessment 11/1/2020 12

Histograms • Along the x-axis you find the categories of concern • If you read over to the y-axis you find the frequency of the category occurring 11/1/2020 13

Pareto Charts • A variant of an histogram • Categories are arranged from greatest frequency of occurrence to least frequent • The cumulative frequency is 1 or 100% 11/1/2020 14

Fishbone (Cause and Effect) Diagrams • Also called Ishikawa Diagram or 4 M Diagram 11/1/2020 15

Fishbone Example • Why are printing errors occurring during the printing of airline tickets? • Maybe the material stock is too thick? Too old? • Maybe the machine is failing with age? Maybe it holds paper too tightly of loosely? 11/1/2020 16

Checksheets • You’re keeping a running tally of the issue (date, time, location) so that the frequencies can be ultimately determined 11/1/2020 17

Scatter Diagrams • Diagram makes relationships (correlation) clearer 11/1/2020 18

Control Charts • • A graphical tool for describing the state of control of a process. Sample values are used to monitor process performance. It’s a confidence interval designed to achieve desired level of producer and consumer risk (type I and type II error). It is used to monitor the output of high volume production processes (repetitive) Construction varies with data type Attribute (0 -1) or Variable (continuous) Means chart, Range chart, P-chart, n. P-chart, c-chart, u-chart, etc. Basic control charts consists of UCL, LCL and centerline X-axis is time while the Y-axis is generally the mean of the quality characteristic being measured. 11/1/2020 19

Which Type of Process Improvement Tool? • • • Sometimes application suggests one type Past experience Other times, more than one type can be used (e. g. , check sheet vs. Pareto diagram below) 11/1/2020 20