EXERCISES FOR LECTURE NOTES-2
1. A router is used to cut registration notches on a printed circuit board. The
vibration at the surface of the board as it is cut is considered to be a major source
of dimensional Variation in the notches. Two factors are thought to influence
vibration: bit size (A) and cutting speed (B). Two bit sizes (1/16 and 1/8 inch) and
two speeds (40 and 90 rpm) are selected, and four boards are cut at each set of
conditions as shown in following table.
𝟐𝟑 Design
a. Estimate the factor effects.
b. Analyze the data from this experiment.
c. What is the estimated regression model?
2. Consider the design of Exercise 1. Suppose that four additional runs were made
at the center of the region of experimentation. The response values at these
center points were 25, 15, 10, and 30. Use this additional information to test for
curvature in the response function. What are your conclusions?
3. An engineer is interested in the effects of cutting speed (A), tool geometry (B),
and cutting angle (C) on the life (in hours) of a machine tool. Two levels of each
factor are chosen, and two replicates of a 23 factorial design are run. The results
are shown in the following table.
a. Estimate the factor effects. Which effects appear to be large?
b. Analyze the data from this experiment.
c. What is the estimated regression model?
4.
5.