How to make two MTBF mutually exclusive?

Question

question

Marcello Rosadini asked Jun 29, '16 Marcello Rosadini commented Jun 29, '16

How to make two MTBF mutually exclusive?

Hi,

I have a model with 2 processors and each of them has 2 types of incidences that happen with different duration and frequencies. "Macro" incidences have duration of (4 to 8) minutes and happen every (42-96min) and "micro" incidences have durations of 1 minute and happen about every (9-18min). I have set 4 tables, one for macro and one for micro for each processor.

I have set a state of "breakdown" for the micro and "down" for the macro incidences.

When running the simulation, the % numbers in breakdown state are quite close (micro incidences) but are way low on the macro incidences.(state down)

My assumption is that, what is happening is that "micro" incidences happen during "macro" incidences, changing the state and thus, the micro are registered properly but the "macro" are cut short...

If this assumption is correct, in reality, this is not what happens. Macro and Micro incidences cannot happen simultaneously. How can I make them mutually exclusive, so that if a macro incidence is happening a micro cannot take place?

If this is not the problem, can someone help me taking a look into the model to get what might be causing trouble?model-v600-29062016-copia.fsm

Software Version:

FlexSim 16.0.1

mtbf mttr

r7lwm.png (7.1 KiB)

model-v600-29062016-copia.fsm (2.7 MiB)

· 1

5 |100000

Attachments: Up to 12 attachments (including images) can be used with a maximum of 23.8 MiB each and 47.7 MiB total.

Matthew Gillespie ♦♦ commented · Jun 29, 2016 at 04:37 PM

You could use Process Flow to control the breakdowns and their interactions with each other. Here's an example of using Process Flow to stop a Processor.

1 ·

Answer 1 · 2016-06-29T10:02:53Z

Jason Lightfoot answered Jun 29, '16 Marcello Rosadini commented Jun 29, '16

You'll need to remove the breakdown/stoppage states from your list of "States Applied to MTBF" - then they should not overlap. In particular your machine enters the "down" state which is listed as a state counting as time between failures, and so it then fails a second time while down. Usually states Breakown and Scheduled Down would also be removed along with 'down'.

· 1

5 |100000

Attachments: Up to 12 attachments (including images) can be used with a maximum of 23.8 MiB each and 47.7 MiB total.

Marcello Rosadini commented · Jun 29, 2016 at 06:09 PM

Thanks for the input, the model is working properly now!

0 ·

question