Known Operating Times - Crow Extended Example - Revision history

Lisa Hacker at 20:53, 18 September 2023

2023-09-18T20:53:30Z

← Older revision		Revision as of 20:53, 18 September 2023
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	<noinclude>{{Banner RGA Examples}}		<noinclude>{{Banner RGA Examples}}
	''This example appears in the [~~[Crow_Extended\|~~Reliability ~~Growth and Repairable System Analysis Reference]~~]''.		''This example appears in the [https://help.reliasoft.com/reference/reliability_growth_and_repairable_system_analysis Reliability growth reference]''.
	</noinclude>		</noinclude>

David J. Groebel at 17:40, 30 May 2014

2014-05-30T17:40:09Z

← Older revision		Revision as of 17:40, 30 May 2014
Line 81:		Line 81:
	<li>The next figure shows the estimated Crow Extended parameters.		<li>The next figure shows the estimated Crow Extended parameters.

	[[Image:rga9.36.png~~\|thumb~~\|center\|~~400px\|Entered data and the estimated Crow Extended parameters.~~]]		[[Image:rga9.36.png\|center\|600px]]
	</li>		</li>
	<li>One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.		<li>One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.

	[[Image:rga9.37.png~~\|thumb~~\|center\|~~400px\|Growth Potential MTBF plot (EF=0.7)~~]]		[[Image:rga9.37.png\|center\|450px]]

	</li>		</li>
Line 92:		Line 92:
	Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.		Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.

	[[Image:rga9.38.png~~\|thumb~~\|center\|~~400px\|Growth Potential MTBF plot (EF=1)~~]]		[[Image:rga9.38.png\|center\|450px]]
	</li>		</li>
	</ol>		</ol>

David J. Groebel at 23:20, 22 April 2014

2014-04-22T23:20:16Z

← Older revision		Revision as of 23:20, 22 April 2014
Line 1:		Line 1:
	<noinclude>{{Banner RGA Examples}}		<noinclude>{{Banner RGA Examples}}
	''This example appears in the [[Crow_Extended\|Reliability Growth and Repairable System Analysis Reference ~~book~~]]''.		''This example appears in the [[Crow_Extended\|Reliability Growth and Repairable System Analysis Reference]]''.
	</noinclude>		</noinclude>

Chris Kahn at 20:47, 6 February 2014

2014-02-06T20:47:03Z

← Older revision		Revision as of 20:47, 6 February 2014
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	Two prototypes of a new design are tested simultaneously. Whenever a failure is observed for one unit, the current operating time of the other unit is also recorded. The test is terminated after 300 hours. All of the design changes for the prototypes were delayed until after completing the test. The data set is given in the table below. Assume a fixed effectiveness factor equal to 0.7. The MTBF goal for the new design is 30 hours. Do the following:		Two prototypes of a new design are tested simultaneously. Whenever a failure is observed for one unit, the current operating time of the other unit is also recorded. The test is terminated after 300 hours. All of the design changes for the prototypes were delayed until after completing the test. The data set is given in the table below. Assume a fixed effectiveness factor equal to 0.7. The MTBF goal for the new design is 30 hours. Do the following:

	1) Estimate the parameters of the Crow Extended model.		#Estimate the parameters of the Crow Extended model.
			#What is the projected MTBF and growth potential?
	2) What is the projected MTBF and growth potential?		#Under the current management strategy, is it even possible to reach the MTBF goal of 30 hours?

	3) Under the current management strategy, is it even possible to reach the MTBF goal of 30 hours?

	{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"		{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"
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	<br>		<br>
	'''Solution'''		'''Solution'''
	<br>		<ol>
	1) The next figure shows the estimated Crow Extended parameters.		<li>The next figure shows the estimated Crow Extended parameters.

	[[Image:rga9.36.png\|thumb\|center\|400px\|Entered data and the estimated Crow Extended parameters.]]		[[Image:rga9.36.png\|thumb\|center\|400px\|Entered data and the estimated Crow Extended parameters.]]
			</li>
	2) One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.		<li>One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.

	[[Image:rga9.37.png\|thumb\|center\|400px\|Growth Potential MTBF plot (EF=0.7)]]		[[Image:rga9.37.png\|thumb\|center\|400px\|Growth Potential MTBF plot (EF=0.7)]]

	3) The current projected MTBF and growth potential MTBF are both well below the required goal of 30 hours. To check if this goal can even be reached, you can set the effectiveness factor equal to 1. In other words, if all of the corrective actions were to remove the failure modes completely, what would be the projected and growth potential MTBF?		</li>
			<li>The current projected MTBF and growth potential MTBF are both well below the required goal of 30 hours. To check if this goal can even be reached, you can set the effectiveness factor equal to 1. In other words, if all of the corrective actions were to remove the failure modes completely, what would be the projected and growth potential MTBF?

	Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.		Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.

	[[Image:rga9.38.png\|thumb\|center\|400px\|Growth Potential MTBF plot (EF=1)]]		[[Image:rga9.38.png\|thumb\|center\|400px\|Growth Potential MTBF plot (EF=1)]]
			</li>
			</ol>

David J. Groebel at 18:24, 27 January 2014

2014-01-27T18:24:16Z

← Older revision		Revision as of 18:24, 27 January 2014
Line 83:		Line 83:
	1) The next figure shows the estimated Crow Extended parameters.		1) The next figure shows the estimated Crow Extended parameters.

	[[Image:rga9.36.png\|thumb\|center\|~~300px~~\|Entered data and the estimated Crow Extended parameters.]]		[[Image:rga9.36.png\|thumb\|center\|400px\|Entered data and the estimated Crow Extended parameters.]]

	2) One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.		2) One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.

	[[Image:rga9.37.png\|thumb\|center\|~~300px~~\|Growth Potential MTBF plot (EF=0.7)]]		[[Image:rga9.37.png\|thumb\|center\|400px\|Growth Potential MTBF plot (EF=0.7)]]

	3) The current projected MTBF and growth potential MTBF are both well below the required goal of 30 hours. To check if this goal can even be reached, you can set the effectiveness factor equal to 1. In other words, if all of the corrective actions were to remove the failure modes completely, what would be the projected and growth potential MTBF?		3) The current projected MTBF and growth potential MTBF are both well below the required goal of 30 hours. To check if this goal can even be reached, you can set the effectiveness factor equal to 1. In other words, if all of the corrective actions were to remove the failure modes completely, what would be the projected and growth potential MTBF?
Line 93:		Line 93:
	Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.		Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.

	[[Image:rga9.38.png\|thumb\|center\|~~300px~~\|Growth Potential MTBF plot (EF=1)]]		[[Image:rga9.38.png\|thumb\|center\|400px\|Growth Potential MTBF plot (EF=1)]]

David J. Groebel at 18:17, 27 January 2014

2014-01-27T18:17:06Z

← Older revision		Revision as of 18:17, 27 January 2014
Line 5:		Line 5:
	Two prototypes of a new design are tested simultaneously. Whenever a failure is observed for one unit, the current operating time of the other unit is also recorded. The test is terminated after 300 hours. All of the design changes for the prototypes were delayed until after completing the test. The data set is given in the table below. Assume a fixed effectiveness factor equal to 0.7. The MTBF goal for the new design is 30 hours. Do the following:		Two prototypes of a new design are tested simultaneously. Whenever a failure is observed for one unit, the current operating time of the other unit is also recorded. The test is terminated after 300 hours. All of the design changes for the prototypes were delayed until after completing the test. The data set is given in the table below. Assume a fixed effectiveness factor equal to 0.7. The MTBF goal for the new design is 30 hours. Do the following:

	:1) Estimate the parameters of the Crow Extended model.		1) Estimate the parameters of the Crow Extended model.
	~~:2) What is the projected MTBF and growth potential?~~
	~~:3) Under the current management strategy, is it even possible to reach the MTBF goal of 30 hours?~~

			2) What is the projected MTBF and growth potential?

			3) Under the current management strategy, is it even possible to reach the MTBF goal of 30 hours?

	{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"		{\|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"
Line 80:		Line 81:
	'''Solution'''		'''Solution'''
	<br>		<br>
	:1) The next figure shows the estimated Crow Extended parameters.		1) The next figure shows the estimated Crow Extended parameters.

	[[Image:rga9.36.png\|thumb\|center\|300px\|Entered data and the estimated Crow Extended parameters.]]		[[Image:rga9.36.png\|thumb\|center\|300px\|Entered data and the estimated Crow Extended parameters.]]

			2) One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.
	:2) One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.

	[[Image:rga9.37.png\|thumb\|center\|300px\|Growth Potential MTBF plot (EF=0.7)]]		[[Image:rga9.37.png\|thumb\|center\|300px\|Growth Potential MTBF plot (EF=0.7)]]

			3) The current projected MTBF and growth potential MTBF are both well below the required goal of 30 hours. To check if this goal can even be reached, you can set the effectiveness factor equal to 1. In other words, if all of the corrective actions were to remove the failure modes completely, what would be the projected and growth potential MTBF?

	:3) The current projected MTBF and growth potential MTBF are both well below the required goal of 30 hours. To check if this goal can even be reached, you can set the effectiveness factor equal to 1. In other words, if all of the corrective actions were to remove the failure modes completely, what would be the projected and growth potential MTBF?		Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.

	:Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.

	[[Image:rga9.38.png\|thumb\|center\|300px\|Growth Potential MTBF plot (EF=1)]]		[[Image:rga9.38.png\|thumb\|center\|300px\|Growth Potential MTBF plot (EF=1)]]

Kate Racaza: Created page with '{{Banner RGA Examples}} ''This example appears in the Reliability Growth and Repairable System Analysis Reference book''. Two prototype…'

2014-01-20T20:29:19Z

Created page with '<noinclude>{{Banner RGA Examples}} ''This example appears in the Reliability Growth and Repairable System Analysis Reference book''. </noinclude> Two prototype…'

New page

<noinclude>{{Banner RGA Examples}}
''This example appears in the [[Crow_Extended|Reliability Growth and Repairable System Analysis Reference book]]''.
</noinclude>

Two prototypes of a new design are tested simultaneously. Whenever a failure is observed for one unit, the current operating time of the other unit is also recorded. The test is terminated after 300 hours. All of the design changes for the prototypes were delayed until after completing the test. The data set is given in the table below. Assume a fixed effectiveness factor equal to 0.7. The MTBF goal for the new design is 30 hours. Do the following:

:1) Estimate the parameters of the Crow Extended model.
:2) What is the projected MTBF and growth potential?
:3) Under the current management strategy, is it even possible to reach the MTBF goal of 30 hours?

{|border="1" align="center" style="border-collapse: collapse;" cellpadding="5" cellspacing="5"
|-
|colspan="5" style="text-align:center"|'''Multiple Systems (Known Operating Times) Data'''
|-
!Failed Unit ID
!Time Unit 1
!Time Unit 2
!Classification
!Mode
|-
|1|| 16.5|| 0|| BD|| seal leak
|-
|1|| 16.5|| 0|| BD|| valve
|-
|1|| 17|| 0|| A||
|-
|2|| 20.5|| 0.9|| A||
|-
|2|| 25.3|| 3.8|| BD|| hose
|-
|2|| 28.7|| 4.6|| BD|| operator error
|-
|1|| 41.8|| 14.7|| BD|| bearing
|-
|1|| 45.5|| 17.6|| A||
|-
|2|| 48.6|| 22|| A||
|-
|2|| 49.6|| 23.4|| BD|| seal leak
|-
|1|| 51.4|| 26.3|| A||
|-
|1|| 58.2|| 35.7|| BD|| seal leak
|-
|2|| 59|| 36.5|| A||
|-
|2|| 60.6|| 37.6|| BD|| hose
|-
|1|| 61.9|| 39.1|| BD|| seal leak
|-
|1|| 76.6|| 55.4|| BD|| bearing
|-
|2|| 81.1|| 61.1|| A||
|-
|1|| 84.1|| 63.6|| A||
|-
|1|| 84.7|| 64.3|| A||
|-
|1|| 94.6|| 72.6|| A||
|-
|2|| 100|| 78.1|| BD|| valve
|-
|1|| 104|| 81.4|| BD|| bearing
|-
|2|| 104.8|| 85.9|| BD|| spring
|-
|2|| 105.9|| 87.1|| BD|| operator error
|-
|1|| 108.8|| 89.9|| BD|| hose
|-
|2|| 132.4|| 119.5|| BD|| spring
|-
|2|| 132.4|| 150.1|| BD|| operator error
|-
|2|| 132.4|| 153.7|| A||
|}

<br>
'''Solution'''
<br>
:1) The next figure shows the estimated Crow Extended parameters.

[[Image:rga9.36.png|thumb|center|300px|Entered data and the estimated Crow Extended parameters.]]

:2) One possible method for calculating the projected MTBF and growth potential is to use the Quick Calculation Pad, but you can also view these two values at the same time by viewing the Growth Potential MTBF plot, as shown next. From the plot, the projected MTBF is equal to 16.87 hours and the growth potential is equal to 18.63 hours.

[[Image:rga9.37.png|thumb|center|300px|Growth Potential MTBF plot (EF=0.7)]]

:3) The current projected MTBF and growth potential MTBF are both well below the required goal of 30 hours. To check if this goal can even be reached, you can set the effectiveness factor equal to 1. In other words, if all of the corrective actions were to remove the failure modes completely, what would be the projected and growth potential MTBF?

:Change the fixed effectiveness factor to 1, then recalculate the parameters and refresh the Growth Potential plot, as shown next. Even if you assume an effectiveness factor equal to 1, the growth potential is still only 27.27 hours. Based on the current design process, it will not be possible to reach the MTBF goal of 30 hours. Therefore, you have two options: start a new design stage or reduce the required MTBF goal.

[[Image:rga9.38.png|thumb|center|300px|Growth Potential MTBF plot (EF=1)]]