Example Using SCT to Analyze Standby with Delay - Revision history

Richard House at 07:24, 7 August 2012

2012-08-07T07:24:12Z

← Older revision		Revision as of 07:24, 7 August 2012
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	The purpose of this example is to illustrate how to model standby with delay using State Change Triggers (SCT).		The purpose of this example is to illustrate how to model standby with delay using State Change Triggers (SCT).

	~~<br>~~
	'''Problem Statement'''		'''Problem Statement'''
	~~<br>~~

	Three devices A, B and C are in parallel. 2 out of 3 are required to perform the task. Initially A and B are working and C is in standby status. If A or B fails, C will replace		Three devices A, B and C are in parallel. 2 out of 3 are required to perform the task. Initially A and B are working and C is in standby status. If A or B fails, C will replace
	the failed one with some delay. After the failed device is restored, it will become a standby device. For example, if A fails, with 10 hours delay C will become active and replace A. After A is restored, it will become a standby device for B and C.		the failed one with some delay. After the failed device is restored, it will become a standby device. For example, if A fails, with 10 hours delay C will become active and replace A. After A is restored, it will become a standby device for B and C.

	~~<br>~~
	'''BlockSim Solution'''		'''BlockSim Solution'''
	~~<br>~~

	The BlockSim modeling of this system is shown in the figure below.		The BlockSim modeling of this system is shown in the figure below.
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	The repair duration for Blocks A, B and C is 30 hours.		The repair duration for Blocks A, B and C is 30 hours.

	~~<br>~~
	'''Block Up/Down Plot'''		'''Block Up/Down Plot'''
	~~<br>~~

	The system event log is shown in the figure below and is as follows:		The system event log is shown in the figure below and is as follows:
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	#...		#...

	~~<br>~~ [[Image:SCT with delay Up Down plot.png\|center\|400px]]		[[Image:SCT with delay Up Down plot.png\|center\|400px]]

Melinda Caroline at 05:11, 6 August 2012

2012-08-06T05:11:11Z

← Older revision		Revision as of 05:11, 6 August 2012
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	<noinclude>{{Banner BlockSim Examples}}		<noinclude>{{Banner BlockSim Examples}}</noinclude>
	~~''This example appears in the [[Repairable_Systems_Analysis_Through_Simulation#State_Change_Triggers\|System Analysis Reference book]]''.~~
	</noinclude>

	The purpose of this example is to illustrate how to model standby with delay using State Change Triggers (SCT).		The purpose of this example is to illustrate how to model standby with delay using State Change Triggers (SCT).

Lisa Hacker at 03:03, 2 August 2012

2012-08-02T03:03:43Z

← Older revision		Revision as of 03:03, 2 August 2012
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	</noinclude>		</noinclude>

	The purpose of this example is to illustrate how to model standby with delay using SCT.		The purpose of this example is to illustrate how to model standby with delay using State Change Triggers (SCT).

	<br>		<br>

Lisa Hacker: /* Block Up/Down plot */

2012-08-02T03:03:25Z

Block Up/Down plot

← Older revision		Revision as of 03:03, 2 August 2012
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	The repair duration for Blocks A, B and C is 30 hours.		The repair duration for Blocks A, B and C is 30 hours.

	~~====  ~~Block Up/Down ~~plot ====~~		<br>
			'''Block Up/Down Plot'''
			<br>

	The system event log is shown in the figure below and is as follows:		The system event log is shown in the figure below and is as follows:

Lisa Hacker at 03:02, 2 August 2012

2012-08-02T03:02:56Z

← Older revision		Revision as of 03:02, 2 August 2012
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	The purpose of this example is to illustrate how to model standby with delay using SCT.		The purpose of this example is to illustrate how to model standby with delay using SCT.

	~~==== Description ====~~		<br>
			'''Problem Statement'''
			<br>

	Three devices A, B and C are in parallel. 2 out of 3 are required to perform the task. Initially A and B are working and C is in standby status. If A or B fails, C will replace		Three devices A, B and C are in parallel. 2 out of 3 are required to perform the task. Initially A and B are working and C is in standby status. If A or B fails, C will replace
	the failed one with some delay. After the failed device is restored, it will become a standby device. For example, if A fails, with 10 hours delay C will become active and replace A. After A is restored, it will become a standby device for B and C.		the failed one with some delay. After the failed device is restored, it will become a standby device. For example, if A fails, with 10 hours delay C will become active and replace A. After A is restored, it will become a standby device for B and C.

	~~====~~ BlockSim Solution ~~====~~		<br>
			'''BlockSim Solution'''
			<br>

	The BlockSim modeling of this system is shown in the figure below.		The BlockSim modeling of this system is shown in the figure below.

Lisa Hacker at 09:22, 31 July 2012

2012-07-31T09:22:43Z

← Older revision		Revision as of 09:22, 31 July 2012
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	#...		#...

	<br> [[Image:SCT with delay Up Down plot.png\|center\|400px]]		<br> [[Image:SCT with delay Up Down plot.png\|center\|400px]]

	~~[[Category:BlockSim_Examples~~]]

Lisa Hacker: Created page with '{{Banner BlockSim Examples}} ''This example appears in the System Analysis Reference book''. <…'

2012-07-31T09:22:23Z

Created page with '<noinclude>{{Banner BlockSim Examples}} ''This example appears in the System Analysis Reference book''. <…'

New page

<noinclude>{{Banner BlockSim Examples}}
''This example appears in the [[Repairable_Systems_Analysis_Through_Simulation#State_Change_Triggers|System Analysis Reference book]]''.
</noinclude>

The purpose of this example is to illustrate how to model standby with delay using SCT.

==== Description ====

Three devices A, B and C are in parallel. 2 out of 3 are required to perform the task. Initially A and B are working and C is in standby status. If A or B fails, C will replace
the failed one with some delay. After the failed device is restored, it will become a standby device. For example, if A fails, with 10 hours delay C will become active and replace A. After A is restored, it will become a standby device for B and C.

==== BlockSim Solution ====

The BlockSim modeling of this system is shown in the figure below.

[[Image:SCT_with_delay_system.png|center|350px]]

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 standard deviation 0.0000001 hours). They operate even if the system is down and repair durations for them are 0 (immediate repair). Block AA(BB/CC) belongs to maintenance group AA(BB/CC). They all have state change triggers. The initial state for each 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 belongs to maintenance group A. It has state change triggers. The initial state is ON; the state upon repair is "Default OFF unless SCT overridden." If Block BB or Block CC goes down, Block A is activated.

Block B fails every 200 hours. It belongs to maintenance group B. It has state change triggers. The initial state is ON; the state upon repair is "Default OFF unless SCT overridden." If Block AA or Block CC goes down, Block B is activated.

Block C fails every 300 hours. It belongs to maintenance group C. It has state change triggers. The initial state is OFF; the state upon repair is "Default OFF unless SCT overridden." If Block BB or Block AA goes down, Block C is activated.

The repair duration for Blocks A, B and C is 30 hours.

====  Block Up/Down plot ====

The system event log is shown in the figure below and is as follows:

#At 100 hours, Block A fails and activates Block AA.
#At 110 hours, Block AA fails and activates Block C.
#At 230 hours, Block B fails and activates Block BB.
#At 240 hours, Block BB fails and activates Block A.
#At 340 hours, Block A fails and activates Block AA.
#At 350 hours, Block AA fails and activates Block B.
#...

<br> [[Image:SCT with delay Up Down plot.png|center|400px]]

[[Category:BlockSim_Examples]]