IE 405 QUALITY MANAGEMENT

1. IE 405 QUALITY MANAGEMENT -2k factorial experiments -Reliability 24.12.2002

2. What is a factorial experiment?

3. Effect of a factor • Change in response produced by a change in the level of that factor averaged over the levels of the other factor(s). • Magnitude and direction of factor effects are to be examined to see which are likely to be important.

4. INTERACTION • Exists if the difference in response between the levels of one factor is not the same at all levels of the other factor(s). • Calculated as the average difference between the effect of A at high level of B and the effect of A at the low level of B.

5. Rec9/Q12k experiment; 3 trials

6. Rec9/Question 1

7. Formulation: MAIN EFFECT OF A MAIN EFFECT OF B INTERACTION EFFECT OF BOTH FACTORS

8. Rec9/Question 1 • Main effect of A: 8.33 • Main effect of B: -5 • Interaction effect of AB: 1.67 • Effect of A is positive it will increase yield. • Effect of B is negative:Increased amount of catalyst will decrease yield. • Interaction seems small relative to the other two effects.

9. What is the difference between SPC and Reliability? • SPC:Concerned with monitoring processes to ensure that manufactured product conforms to specifications. • Variables of interest: No. of defects and degree of conformance variation • Reliability:Considers the performance of a product over time. • Variables of interest: The amount of elapsed time between failures after the product is placed into service.

10. Rec9/Q2 • General Reliability formula: R(t)=e –λt • Single component: 1/e • Two components in series : R(t)=e –(λ1 + λ2)t =1/e c)Two components in parallel : 1-[1-R(t)]N = 1-[1-0,135335]2

11. Rec9/Q3

12. Rec9/Q3