BlockSim Example: CM Triggered by Subsystem Down

CM triggered by subsystem down

Purposes

The purposes of this example is to illustrate how to model the case when CM is triggered by failure of subsystem.

Description

Three devices A, B and C are in parallel. A and B form a subsystem. Only both A and B fail (subsystem fails), then start to repair A and B. The repair of C is depend on its failure. When C fails, then start to repair C.

BlockSim Solution

The BlockSim modeling of this system is shown in Figure below.

In order to model the delay, three extra blocks AA, BB and CC are added to the diagram. Each of them fails every 10 hours (Normal distribution with mean 10 hours and standdard deviaiotn 0.0000001 hours). They operate even if system is down and repair durations for them are 0 (immediate repair). Block AA(BB/CC) is belong to maintenance group AA(BB/CC). They all have state change triggers. The initial state is OFF and the state upon repair is Always OFF. If Block A (B/C) goes down, then activate Block AA (BB/CC).

Block A fails every 100 hours. It is belong to maintenance group A. It has state change triggers. The intial state is ON; the state upon repair is Default OFF unless SCT overridden. If Block BB or Block CC goes down, active this block.