1. Quality management Lecture 3.
Quality theories
Quality management
Lecture 3.

2. History of quality management
Early 1920
Scientific management (Taylor, Gilbreth)
1920s
Statistical process control (Shewart)
1930s
Acceptance sampling (Dodge, Roming)
1940s
Military standards introduced
1950s
Quality management in Japan (Deming, Juran)
1960s
Taguchi method, and quality tools
1970s
Quality becomes strategic (USA)
1980s
Introduction of LEAN, TQM, Baldrige Award
1990s
Reengineering, Six Sigma
2000s
Supply chain management, improvement of supplier development, LEAN, Six sigma become popular, contingency theory

3. Quality and taylorism Basics of taylorism Quality effects:
The whole process is divided into short steps (division of labor)
It is not the worker who determine the process/movements -specialist do that (task management)
Workers are selected and trained for work
Standard movements and tools, detailed instructions (standardization)
Quality effects:
Product and process design were separated from the repair of product
Workers were not responsible for repairing of product
Quality control department was established to control the product at the end of the process
The responsibility for quality were spread over in the company

4. Deming
Not just worker but managers have the responsibility for establishing quality
Workers responsible for special problems
Managers responsible for the whole system (proper methods, equipments, motivation system etc.)
Quality improvement must be divided between the two level

5. Juran
Quality problems are rooting in insufficient and ineffective planning for quality
In traditional way:
Planning determine the tools for producing goods
20% of the operating process is waste, it is planned into the product or process
Instead of quality improvement they only do quality control
Juran trilogy
Planning
Control
Improvement

6. Ishikawa
Democratizing statistics: everyone is responsible for statistical analyzes,
total involvement of the operating employees in improving quality
Basic 7 tools of quality
Process map – flow chart, step of process
Check sheet – to collect errors for analyzes
Histogram – graphic representation of data
Scatter Diagrams – examine the relationship between variables (what cause the problem)
Control Chart – is the process stable or not
Cause-and-effect (Ishikawa) diagram – find all reason of the problem, directed tool for find all causes
Pareto Chart – prioritize causes, determine problems must be focused on

7. Feigenbaum Father of Total Quality Control (TQC)
the entire organization should be involved in quality improvement
The quality is poor
If the product is designed incorrectly (engineering)
If the product is released in the wrong market
If the customer relationship is not proper. (marketing)
3 steps of improvement
4 deadly diseases

8. Crosby Crosby’s four theorem
Quality is the conformance to the requirements of customers. The whole system must be developed according to this approach.
The main goal is zero-defect. Do the right product at the first time.
Thus the applied method for quality assurance is prevention not control.
Quality can be a source of profit. Quality costs must be evaluated, and on the basis of these costs, corrective actions should take place.

9. Taguchi
Quality definitions: quality is measured in terms of loss to society if the service not performed as expected.
Quality Loss Function (QLF): any deviation from target value results in loss to society
Robust Design: products should be designed to be defect-free
Concept design (technology and process choices)
Parameter design (select parameters which have an effect on quality – amount of training, heights of a paper)
Tolerance design (deals with decrease variation in order to fulfill the specification limits – use a higher-grade materials)

10. QLF (Qualtiy Loss Function)
L=K*V2
K – constant, and
V2- mean squared dviation from target value
K=C/T2
C - unit repair cost
T – tolerance interval
LSL
Target value
USL

11. Exercise - QLF
Suppose the cost to repair a radiator on an automobile is $200. Compute the QLF for losses incurred as a result of a deviation from target setting where a tolerance of 6±0,5 mm is required and the mean squared deviation from target is (1/6)2.
Solution:
K=200/0,52=800
L=K*V2=800*(1/6)2=$22,22/unit

12. TAGUCHI PROCESS 1. Problem identification 2. Brainstorming session
identify factors, its settings, interactions,
Control factor
Noise factor
Identify objectives
The less is better
Nominal is best
The more is the better
Experimental design
Offline experimentation (number of replications)
Experimentation
Orthogonal array (determined by the number of factors and levels)
Record the result
Compute average performance for each factor
Showing the best outcomes
Analysis (which level of each factor is the proper one)
Confirming experiment (validate results)

13. Contingency theory
There are no schemes, firms do not have to use only one quality approach
Successful firms adopt aspects of each approach that help them improve, understand them, and apply them creatively.
It depends on the situation which approach is the best.

14. Thank you for your attention!