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STATISTICAL PROCESS CONTROL (SPC) FOR CONTINUAL QUALITY IMPROVEMENT

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Total Quality Management ­ MGT510
VU
Lesson # 39
STATISTICAL PROCESS CONTROL (SPC) FOR CONTINUAL QUALITY IMPROVEMENT
Variation and Process Control
In a total quality setting, consistency and predictability are important. When a process runs consistently,
efforts can begin to improve it by reducing process variations, of which there are two kinds:
·
Common-cause variation is the result of the sum of numerous small sources of natural variation
that are always part of the process.
·
Special-cause variation is the result of factors that are not part of the process and that occur only
in special circumstances, such as a shipment of faulty raw material or the involvement of anew,
untrained operator.
The performance of a process that operates consistently can be recorded and plotted on a control chart
such as the one in Figure below. The sources of the variation in this figure that fall within the control
limits are likely to be common causes. The sources of variation in this figure that fall outside the control
limits are likely to be special-causes sources. In making decisions about the process in question, it is
important to separate common and special causes of variation.
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Control Chart
If you react to common-cause variation as if it were due to special causes, you will only make matters
worse and increase variation, defects, and mistakes. If you fail to notice the appearance of a special
cause, you will miss an opportunity to search out and eliminate a source of problems
Control charting in SPC utilizes in-process (sometimes called on-line) sampling techniques to help
monitor a process. The purpose is to indicate when the process is functioning as intended i.e.
statistically under control and when to take corrective action of some type is necessary. Hence SPC can
be taken as a proactive and preventive approach of quality improvement. An in-control process is
considered stable and out-of-control process is said to be un-stable. Improvement in stable system can
occur only through system changes, which are the responsibility of management and empowered
employees. Instability is created when a special cause or disturbance is present. Once an indication of a
process shift is detected it is up to the operators, engineers, and other technical people to locate the
special cause/s and take corrective action.
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Table of Contents:
  1. OVERVIEW OF QUALITY MANAGEMENT:PROFESSIONAL MANAGERIAL ERA (1950)
  2. TOTAL QUALITY MANAGEMENT AND TOTAL ORGANIZATION EXCELLENCE:Measurement
  3. INTEGRATING PEOPLE AND PERFORMANCE THROUGH QUALITY MANAGEMENT
  4. FUNDAMENTALS OF TOTAL QUALITY AND RATERS VIEW:The Concept of Quality
  5. TOTAL QUALITY MANAGEMENT AND GLOBAL COMPETITIVE ADVANTAGE:Customer Focus
  6. TOTAL QUALITY MANAGEMENT AND PLANNING FOR QUALITY AT OFFICE
  7. LEADERS IN QUALITY REVOLUTION AND DEFINING FOR QUALITY:User-Based
  8. TAGUCHI LOSS FUNCTION AND QUALITY MANAGEMENT
  9. WTO, SHIFTING FOCUS OF CORPORATE CULTURE AND ORGANIZATIONAL MODEL OF MANAGEMENT
  10. HISTORY OF QUALITY MANAGEMENT PARADIGMS
  11. DEFINING QUALITY, QUALITY MANAGEMENT AND LINKS WITH PROFITABILITY
  12. LEARNING ABOUT QUALITY AND APPROACHES FROM QUALITY PHILOSOPHIES
  13. TOTAL QUALITY MANAGEMENT THEORIES EDWARD DEMING’S SYSTEM OF PROFOUND KNOWLEDGE
  14. DEMING’S PHILOSOPHY AND 14 POINTS FOR MANAGEMENT:The cost of quality
  15. DEMING CYCLE AND QUALITY TRILOGY:Juran’s Three Basic Steps to Progress
  16. JURAN AND CROSBY ON QUALITY AND QUALITY IS FREE:Quality Planning
  17. CROSBY’S CONCEPT OF COST OF QUALITY:Cost of Quality Attitude
  18. COSTS OF QUALITY AND RETURN ON QUALITY:Total Quality Costs
  19. OVERVIEW OF TOTAL QUALITY APPROACHES:The Future of Quality Management
  20. BUSINESS EXCELLENCE MODELS:Excellence in all functions
  21. DESIGNING ORGANIZATIONS FOR QUALITY:Customer focus, Leadership
  22. DEVELOPING ISO QMS FOR CERTIFICATION:Process approach
  23. ISO 9001(2000) QMS MANAGEMENT RESPONSIBILITY:Issues to be Considered
  24. ISO 9001(2000) QMS (CLAUSE # 6) RESOURCES MANAGEMENT:Training and Awareness
  25. ISO 9001(2000) (CLAUSE # 7) PRODUCT REALIZATION AND CUSTOMER RELATED PROCESSES
  26. ISO 9001(2000) QMS (CLAUSE # 7) CONTROL OF PRODUCTION AND SERVICES
  27. ISO 9001(2000) QMS (CLAUSE # 8) MEASUREMENT, ANALYSIS, AND IMPROVEMENT
  28. QUALITY IN SOFTWARE SECTOR AND MATURITY LEVELS:Structure of CMM
  29. INSTALLING AN ISO -9001 QM SYSTEM:Implementation, Audit and Registration
  30. CREATING BUSINESS EXCELLENCE:Elements of a Total Quality Culture
  31. CREATING QUALITY AT STRATEGIC, TACTICAL AND OPERATIONAL LEVEL
  32. BIG Q AND SMALL q LEADERSHIP FOR QUALITY:The roles of a Quality Leader
  33. STRATEGIC PLANNING FOR QUALITY AND ADVANCED QUALITY MANAGEMENT TOOLS
  34. HOSHIN KANRI AND STRATEGIC POLICY DEPLOYMENT:Senior Management
  35. QUALITY FUNCTION DEPLOYMENT (QFD) AND OTHER TOOLS FOR IMPLEMENTATION
  36. BASIC SQC IMPROVEMENT TOOLS:TOTAL QUALITY TOOLS DEFINED
  37. HOW QUALITY IS IMPLEMENTED? A DIALOGUE WITH A QUALITY MANAGER!
  38. CAUSE AND EFFECT DIAGRAM AND OTHER TOOLS OF QUALITY:Control Charts
  39. STATISTICAL PROCESS CONTROL (SPC) FOR CONTINUAL QUALITY IMPROVEMENT
  40. STATISTICAL PROCESS CONTROL….CONTD:Control Charts
  41. BUILDING QUALITY THROUGH SPC:Types of Data, Defining Process Capability
  42. AN INTERVIEW SESSION WITH OFFICERS OF A CMMI LEVEL 5 QUALITY IT PAKISTANI COMPANY
  43. TEAMWORK CULTURE FOR TQM:Steering Committees, Natural Work Teams
  44. UNDERSTANDING EMPOWERMENT FOR TQ AND CUSTOMER-SUPPLIER RELATIONSHIP
  45. CSR, INNOVATION, KNOWLEDGE MANAGEMENT AND INTRODUCING LEARNING ORGANIZATION