BlockSim Example: Phase with Failure or Success Paths

Purposes
The purposes of this example is to illustrate how to apply F/S links in Phase simulation.


 * 1) For a F link, on system failure, system go to somewhere immediately when failure occurs.
 * 2) For a S link, if there is no system failure during this phase, system goes to somewhere by the end of the current phase.

RBDs for Phase and settings
The RBDs for Phase 1 and Phase 2 are as followings:

In Phase 1, Block A follows Weibull distribution with Beta = 1.5 and Eta = 1000 hours. Block B follows Weibull distribution with Beta = 1.5 and Eta = 1200 hours. No maintenance.

In Phase 2, Block A follows Weibull distribution with Beta = 1.5 and Eta = 900 hours. Block B follows Weibull distribution with Beta = 1.5 and Eta = 1150 hours. No maintenance.

Example 1
The Phase diagram is as followings:

Maintenance phase has a CM with duration 80 hours and PM with duration 20 hours for both Block A and B.

Phase 1 has duration 500 hours and Phase 2 has duration 100 hours.

If there is no failure in Phase 1, upon finish, it goes to Phase 2. If there is a failure in Phase 1, it would go to Maintenance Phase 3 immediately. If there is no failure in Phase 2, upon finish, it goes back to Phase 1. If there is a failure in Phase 2, it would go to Maintenance Phase 3 immediately.

The Block Up/Down plot is as followings:


 * 1) At the first cycle (0-500 for Phase 1 and 500-600 for Phase 2), there is no failure, thus after Phase 2, Phase 1 is executed (back to Phase 1 after this cycle).
 * 2) At 1135 (Phase 2 of the second cycle), Block A fails. System doesn't enter Maintenance Phase 3 immediatly because in Phase 2, Block A and Block B are parallel. Only failure of Block A doesn't bring system down.
 * 3) At 1200, system finishes Phase 2 and goes back to Phase 1. There is not system failure in Phase 2 (only failure is failure of Block A and this failure doesn't bring system down). In Phase 1, Block A and Block B are in series. Failure of Block A passed from Phase 2 will bring system down in Phase 1. Thus there is a system failure in Phase 1 and system goes to Maintenance Phase 3 immediatly. Block B is not down, thus it gets PM with duration 20 hours. Block A gets CM with duration 100 hours.
 * 4) At 2738, Block A fails in Phase 1 and bring system down immediatly. System goes into Maintenance Phase 3 immediatly. Block A gets CM and Block B gets PM.



Example 2
The Phase diagram is as followings:

Everything is the same as that in Example 1 except that the link from Phase 2 to Maintenance Phase 3 changes from F link to S link. This means that whether or not there is a failure in Phase 2, the system would go to Maintenance Phase 3 after Phase 2. But if there is a failure in Phase 2, system would go to Maintennace Phase 3 after Phase 2, not immediately.

The Block Up/Down plot is as followings:


 * 1) At the first cycle (0-500 for Phase 1 and 500-600 for Phase 2), there is no failure, thus after Phase 2, the system go to Maintennace Phase 3 for PM for both Block A and B with duration 20 hours.
 * 2) At 1171, Block A fails in Phase 2. Due to the parallel system structure in this phase, this failure doesn't bring system down. However, after Phase 2, system still go to Maintenance Phase 3.
 * 3) At 2835, Block A fails in Phase 1. Due to the series system structure in this phase, this failure bring the system down and thus system go to Maintenance Phase 3 immediately. [[Image:Phase Up Down plot for Example 2.png|thumb|center|500px]]