RAM Commander supports Frequency (unconditional failure intensity) at time t W(t) calculation.

 

The frequency w(t) for each particular basic event is calculated based on formulas specified in events list table in paragraph Basic Event Types earlier in this chapter.

 

To calculate the W(t) for top gate we need to generate Minimal Cut-Sets list first.

 

Then the following formulas are implemented:

 

Unconditional failure intensity of the specific MCS with number j is:

where

 MCS[1],…,MCS[j],…,MCS[m] – minimal cut set

 n[j] – amount of Basic Events of the MCS number j;

 f[i_j](t) – unavailability Q(t) of the BE with number i_j at the time t;

 w[i_j](t) – frequency of the BE with number i_j at the time t;

 

Unconditional failure intensity of the top gate of the fault tree:

where

 MCS[1],…,MCS[j],…,MCS[m] – minimal cut set;

 W_MCS[j] - Unconditional failure intensity of the specific MCS with number j;

 F_MCS[j] - unavailability Q(t) of the specific MCS with number j.