140 ◾ System Instantaneous Availability
6.2.3 Availability Amplitude and Occurrence
Time of Minimum Availability
For an unmatched system, a large amount of numerical simulation indicates that
the volatility of system instantaneous availability usually decreases over time and
trends to zero. However, in the initial period, the volatility degree of availability is
different. In order to better describe the volatility characteristics of a system, two
following concepts are given.
Definition 6.4: Definition
min()
min
k
k
is the minimum availability of
the system, which occurs at the time of
min|() 0.
in
Ak A
When the minimum value of A(t) does not occur within a finite time, T
0
= N.
Definition 6.5: e maximum availability amplitude is de ...