SE-534 Advance Quality Control

By S. O. Duffuaa

Course Objectives



Enable students to model, solve and analyze complex quality Control Problems.

Course Outcomes

 Present and critique the main quality control approaches  Formulate models for the design of inspection plans and implement methods for solving these models.

 Formulate models for the design of control charts and implement methods for solving these models.

Course Outcomes

 Incorporate Taguchi approach in the design of inspection plans and control charts.

 Identify assumptions made in published literature, relax some of them and incorporate their effect in research papers.

Text Book and References

   1. "Introduction to Statistical Quality Control" by Douglas Montgomery, 2nd Edition, 1991, John Wiley.

"Quality Engineering in Production Systems“ by G. Taguchi, E. Elsayed, T. Hsiang, McGraw Hill 1989.

IIE Transactions, European Journal of Operational Research, Journal of Quality Technology, International Journal of Production Research, International Journal of Quality and Reliability Quality Management.

Course Policy



Home work 10%



Team Discussions/presentations 10%



Term Paper



Mid term Exam



Final Exam 25% 25% 30%

Major Area and Topics



Statistical & Quality background

(2) 

Advances in product Control - Inspection Plans (8)



Process Control (6)



Process Targeting (6)



Adaptive Quality Control and quality Engineering (8)



Integrated Quality Models.

Background

 Random variables  Probability distribution  Functions of random variables  central limit theorem  Confidence estimation  Basic ideas of quality and quality improvement

Basics of Quality

 What is quality?

 Fitness for purpose or use (Juran)  Conformance to requirement specifications ( Crosby) 

Quality

is the ability of a product or service to consistently meet or exceed customer expectations (Textbook and ASQ ).

Basics of Quality

 A product or service's nature or features that reflect capacity to satisfy express or implied statements of need ( Deming).

 A product and service characteristics as offered by design, marketing, manufacture, maintenance and service that meet customer expectations ( Feigenbaum )

Quality Basics

 GSA defines it as: “ Meeting the customer needs the first time and every time”.

 Boeing defines it as: “ Providing our customer with products and services that consistently meet the needs and the expectation”.

 Federal Express Defines it as : “ Performance to the standard expected by customer”.

Basics of Quality

 Quality is not only product and services but also include Processes, Environment and People. Therefore a more general definition is needed “ Quality is a dynamic state associate with products, people, processes and environment that meets or exceeds customer expectations”An extended definition of quality is: “

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



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

Examples of Quality Dimensions

Table 9-1

Dimension

1. Performance 2. Aesthetics

(Product) Automobile (Service) Auto Repair

Everything works, fit & finish Ride, handling, grade of materials used Interior design, soft touch All work done, at agreed price Friendliness, courtesy, Competency, quickness Clean work/waiting area 3. Special features Convenience High tech Gauge/control placement Cellular phone, CD player Location, call when ready Computer diagnostics 4. Safety Antilock brakes, airbags Separate waiting area

Examples of Quality Dimensions

Table 9-1

(Cont’d)

Dimension (Product) (Service) Automobile Auto Repair 5. Reliability Infrequency of breakdowns Work done correctly, ready when promised 6. Durability Useful life in miles, resistance to rust & corrosion Work holds up over time 7. Perceived quality Top-rated car Award-winning service department 8. Service after sale Handling of complaints and/or requests for information Handling of complaints

What is Quality

 Quality of a function of many variables that include: cost, reliability, durability, serviceability, safety, conformance, performance, etc …

Approaches to Quality

• Inspection • • • • Single Double Multiple Sequential • • • Process Control Process targeting Quality Engineering