ABSTRACT
As described in Chapter 1, statistical process control (SPC) is a major statistical tool
for monitoring a production process to make sure that it works stably. The stability of
the production process is reflected by the conformance of the quality characteristics
of its products to their designed requirements. Because the quality characteristics
are affected by both controllable and uncontrollable input variables of the produc-
tion process (cf., Figure 1.1), observations of the quality characteristics would have
random noise involved, which represents the common cause variation in the quality
characteristics (cf., the related discussion in Section 1.3). To describe and analyze
such data with random noise, the use of various statistical concepts and methods is
necessary, and is briefly introduced in this chapter.
