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Failure repair process flow

How to assign failure and repair times (MTBF and MTTR) to individual stations connected in series.


flexsim 21.1.4
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Hi @Prashant T2, was Felix Möhlmann's answer helpful? If so, please click the red "Accept" button at the bottom of their answer. Or if you still have questions, add a comment and we'll continue the conversation.

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Felix Möhlmann answered Felix Möhlmann commented

What is missing to your solution is a way to tell the "breakdown token" which token to release and to differentiate between the case when a token is already using the station or not.

For this purpose I added an array as a label "stationTokens" of the process flow. When a token pulls a station, I change the entry for that station's index to a reference to the token. This way the "breakdown tokens" can check whether they should pull a token to the "Waiting Area" and which one.

If there is no token they simply pull the station themselves to prevent other tokens from using it for the duration of the repair.

I create one "breakdown token" for each station and have them loop through the "wait for breakdown - repair" cycle.

multistation2_1.fsm


multistation2-1.fsm (38.3 KiB)
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Hi, when I run this model with frequent failures and repairs, I see that at times the stations are not moved back from the 'Waiting Area'. Please see the model between the simulation time 880 - 920 seconds. Do you know what can be the reason for this? Thank you for the help.


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Picture4.PNG

multistation2-1.fsm

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multistation2-1.fsm (39.7 KiB)

I made a small error. I didn't consider the order of pulling the station from the list and adding the token to the array. What happens is that the entry in the array gets overwritten by another token. So the "new" token gets "restored" to the state of the old one that stays in the "waiting area".

The "Add to Array" and "Remove from Array" activities should be nested inside the pull from list and push to list.

movedactivities.png

multistation2-1_1.fsm

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