Page 51 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

Section I.8 Quality Assurance and Total Quality Management

(8) (D)

FIGURE l.|I Machining a mold cavity for making sunglasses. la) Computer model of the sunglasses as designed
and viewed on the monitor. (b) Machining of the die cavity, using a computer numerical control milling machine
Source: Courtesy of Mastercam/CNC Software, Inc.

1.8 Quality Assurance and Total Quality Management

Product quality is one of the most critical aspects of manufacturing, because it di-
rectly influences customer satisfaction, thus playing a crucial role in determining a
product’s success in the global marketplace (Chapter 36). The traditional approach
of inspecting products after they are made has largely been replaced by the recogni-
tion that quality must be built into the product from its initial design through all
subsequent stages of manufacture and assembly.
Because products are typically made through several manufacturing steps and op-
erations, each step can involve its ovvn significant variations in performance, which can
occur even Within a relatively short time. A production machine, for example, may per-
form differently vvhen it is first turned on than when it warms up during its use or When
the ambient temperature in the plant fluctuates. Consequently, continuous control of
processes (known as online monitoring) is a critical factor in maintaining product qual-
ity, and the objective must be to control processes, not products.
Quality assurance and total quality management (TQM) are widely recognized
as being the responsibility of everyone involved in the design and manufacture of
products and their components. Product integrity is a term generally used to define the
degree to which a product
° Functions reliably during its life expectancy, as shown in Table 1.4,
° Is suitable for its intended purposes, and
° Can be maintained with relative ease.