Page 235 - Sensors and Control Systems in Manufacturing

Networking of Sensors and Contr ol Systems in Manufacturing
manufacturing equipment containing sensory and control systems 195
generally becomes more expensive as the processing time is reduced.
Tradeoffs are generally necessary among improvements in the five
parameters and the cost of equipment. If high-performance equip-
ment is to be employed, the factory configuration must make effec-
tive use of the equipment’s capabilities to justify its higher cost. On
the other hand, if the factory configuration does not require the high-
est parameters, then it is far more cost-effective to choose equipment
units that are less sophisticated but adequate for the purposes of the
facility. This interplay between parameter values and equipment
design and cost is an essential aspect of system design.
Table 4.1 illustrates the difference between available parameter
values and optimum parameter values, where the subscripts for
equipment E represent increasing levels of complexity. The table
shows the type of data that can be collected to evaluate cost and ben-
efits. These data have significant impact on system design and perfor-
mance which, in turn, have a direct impact on product cost. Given the
type of information in Table 4.1, system designers can evaluate the
effects of utilizing various levels of sensors and control systems on
new equipment and whether they improve performance enough to be
worth the research and development and production investment.

R&D Equipment
Expense, Cost,
MTOI, MTI, Yield, Process, Thousands Thousands
Equipment min min % min of Dollars of Dollars
Production Function A
E 0.1 0.1 90 12 50
1
E 1.0 0.1 85 8 75
2
E 10 1.0 80 10 85
3
E 18 1.0 90 8 280 155
4
Production Function B
E 1.0 0.1 95 10 150
1
E 10 0.5 90 2 300
2
Production Function C
E 0.1 0.1 98 3 125
1
E 5.0 1.0 98 2 250
2
E 8.0 2.0 96 1 300
3
E 20 2.0 96 1 540 400
4
TABLE 4.1 Values of Available Parameters