MTBF MTTR without Down Time in process flow

Question

question

Cesar C5 asked Dec 6, '20 Ben Wilson commented Dec 11, '20

MTBF MTTR without Down Time in process flow

Model:

I set the First Failure Time, Down Time and Up Time of ProcessA using MTBF MTTR from the toolbox, but I only want to use the First Failure Time and Up Time, because instead of Down Time I want to simulate the repair process, that is, when ProcessA fails it will be stop indefinitely and it only can be resumed after the repair process is done by ProcessB and a operator transports and "installs" the repaired parts in ProcessA.

This is what I have in Process Flow:

img_001.JPG

stop_resume_object.fsm

Stop Object and Resume Object custom code is used to ignore Down Time, the problem is that this custom code only takes effect in the first failure, after that Down Time is used instead, ignoring the repair process.

I would appreciate if you can point what I'm doing wrong or show me if there is another way to do it. Thank you.

Software Version:

FlexSim 20.2.3

processflow flexsim 20.2.3

img-000.jpg (32.5 KiB)

img-001.jpg (59.9 KiB)

stop-resume-object.fsm (45.6 KiB)

· 1

Ben Wilson ♦♦ commented · Dec 11, 2020 at 02:35 PM

Hi @Cesar C5, was jason.lightfoot's or Gokulakrishnan Kandasamy's answer helpful? If so, please click the red "Accept" button on one of their answers. Or if you still have questions, add a comment and we'll continue the conversation.

If we haven't heard back from you within 3 business days we'll auto-accept an answer, but you can always unaccept and comment back to reopen your question.

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Answer 1 · 2020-12-07T23:00:53Z

Jason Lightfoot answered Dec 7, '20

What you had was fine, but to get it to work as you wanted you should make a couple of changes.

First - change the Resume function to Do Nothing as you do this in your ResumeObject activity.

Next you should make the MTBF/MTTR based on state Processing so that it doesn't generate a second failure while it's stopped.

And then because the processor is stopped by the MTBF/MTTR, you don't need to stop it yourself or acquire the processor. So your process flow can be just this:

Model attached.

stop-resume-objec_jl.fsm

1607381912672.png (3.1 KiB)

1607381943705.png (7.2 KiB)

1607382007395.png (21.3 KiB)

stop-resume-objec-jl.fsm (44.4 KiB)

Answer 2 · 2020-12-06T07:42:45Z

Gokulakrishnan Kandasamy answered Dec 6, '20 Cesar C5 commented Dec 6, '20

@Cesar C5 I have a look into the model. You can use the interarrival time to define the failure time(MBTF) and to add MTTR you can use the process time of processor B. I have recreated your model. Please look into your model. Let me know if you have any doubt stop-resume-object_gk.fsm

Regards

GK

stop-resume-object-gk.fsm (44.3 KiB)

· 1

Cesar C5 commented · Dec 06, 2020 at 09:47 AM

Thank you, I tried the same with no success, this helped me a lot.

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