Exercise 1

Section 2 Variation Fundamentals

Lesson S02-10

Text: Section 9 pages 1 – 4

Duration: 18 minutes

In the workbook, find and work the questions in exercise 1. The following videos include suggested answers and discussion. You will also find the text of each question above the corresponding answer/discussion video.

Introduction to Exercise 1

a. Key Characteristic Data always follows a normal distribution (true/false).

Solution/Discussion: Exercise 1 a

b. For a Normal distribution, what percentage of the population falls within one standard deviation of the mean?

c. For a Normal distribution, what percentage of the population falls within three standard deviations of the mean?

Solution/Discussion: Exercise 1 b & c

d. What is the difference between control limits and specification limits?

e. Who determines control limits?

Solution/Discussion: Exercise 1 d & e

f.  What term do we use to describe sources of variation that cause unexpected changes in a process?

Solution/Discussion: Exercise 1 f

g. Which distribution do individual values follow?

Solution/Discussion: Exercise 1 g

h. Which distribution do averages from a stable process follow?

Solution/Discussion: Exercise 1 h

i. Does “in control” imply “in spec?”

j. What is another word for the term “out of control?”

Solution/Discussion: Exercise 1 i & j

k. Please define Quality.

l. How does variability among individuals compare to variability among averages? Please state the relationship mathematically and in words.

Solution/Discussion: Exercise 1 k & l

m. The process below is “in-control.” (True, False, Cannot Tell)

n. Does the following graphic represent an “in control” process?

Solution/Discussion: Exercise 1 m & n

o. Does the following graphic represent an “in control” process?

p. A stable process implies that the process is also capable (true/false).

q. Describe the difference between process stability and process capability.

Solution/Discussion: Exercise 1 o, p & q