X20 system modules • Other functions • X20CM4810
X20 system User's Manual 3.10
2099
Example
This example will use the first and second derivative to determine the best time for repairs. The maximum service
life will be taken into account when selecting a time to perform a replacement. The possibility of lowered production
quality is not taken into consideration.
Various times for performing a replacement can be selected by referring to the trend progression.
•
k1 = First increase. Very conservative, service life is wasted.
•
k2 = Second increase. Good compromise between conservative and optimal.
•
k3 = Drop in second derivative. Optimal utilization of service life.
Information:
This example of derivative usage should not be used in your own applications.
First derivative
27.01
16.02
04.03
24.04
13.05
01.06
0
0.5
1
1.5
2
2.5
3
3.5
??
Time
Failure
k2
k1
Figure 669: First derivative of the trend progression
Second derivative
27.01
16.02
04.03
24.04
13.05
01.06
-0.2
0.6
??
Time
0.4
0.2
0
-0.4
-0.6
-0.8
-1
-1.2
Failure
k2
k3
Figure 670: Second derivative of the trend progression
