Page 317 - Improving Machinery Reliability

Life Cycle Cost Studies 287

C
Last Best Last New Best
PI It Plant Parameter Plant Plant Plant
I
Availability 0.95 0.95 0.98
Reliability 0.3 0.4 0.6
Tradeoff
Maintainability 0.7 0.7 0.7
Capability 0.7 0.8 0.6
Sys. Effect. 0.14 0.22
A
80 loo
System Effectiveness

Figure 5-10. Benchmark data shown in trade-off format.

(A) (B)
A is preferable: A is preferable:
effectiveness is equal cost is equal
A costs less A is more effective
LCC LCC
I1 B A
n

-
System Effectiveness System Effectiveness

(C) (D)
A is preferable: A is preferable AE
A costs less is worth more than AC:
A is more effective A is more effective
LCC LCC B costs less
A

System Effectiveness System Effectiveness

Figure 5-1 1. Some possible outcomes from trade-off studies.