Average throughput time of a flow item?

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Oliver H asked Jun 28, '17 Nurul Ain bt Ismayudin I commented Aug 22, '21

Average throughput time of a flow item?

Hi there,

I have a simulation of a production and assembly line. it starts with the raw material of one part being delivered to the entry of the system, and ends with the sink after the assembly line.

how can i count the throughput time of ONE flow item, the waiting time and the process time? all of these 3 numbers should have minimum, maximum and average.

thanks in advance.

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process time throughput waiting times average

Answer 1 · 2017-06-29T10:17:53Z

Jeff Nordgren answered Jun 29, '17 Oliver H commented Jun 30, '17

@Oliver H

I'll admit, I'm not quite sure why the "stats" on one single flowitem would be of much use in a simulation model. I guess that's why there isn't an "automatic" way of doing it, to my knowledge. But there is always a way to do something that may not be the "norm". Attached is a model that will track those stats as labels on each flowitem. I'm sure there are more than one way that this could be accomplished. The attached model is just one way.

In the Source, OnCreation, I create all the labels on the flowitems. Then in the Queues, I track the time into the Queue in the OnEntry trigger and calculate the wait time in the OnExit trigger.

In the Processors, after the process time is calculated I use that time to write those stats to the item's labels.

There are 2 User Commands, the WaitStats and the ProcStats. These are called from the Queues and the Processors to calculate the stats for the flowitem.

If you double click on any flowitem in the last queue (last item in stops the model run), you can see the stats for that flowitem

I hope this is what you were looking to do? If you have any questions, please let us know.

Thanks.

oneitemtracking-jn1.fsm

oneitemtracking-jn1.fsm (22.7 KiB)

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Oliver H commented · Jun 29, 2017 at 10:33 AM

@Jeff Nordgren

Thank you for your answer.

My english is not that well, maybe i caused a misunderstanding.

I have the production and assembly line, from which i have approximately 40 orders a day. i want to count the throughput time of all the flow items, and have it show me the minimum time (fastest throughput of one item), the maximum time (slowest throughput of one item) and the mean throughput time.

i have found something, but this shows me the sum of all throughput times, so if the mean throughput time is 10min, on the first day it shows me 10 min, on the second 20min, on the third 30min and so on.

i will check on your model later this day, thank you for helping out. i will soon tell you if i managed.

best regards,

Oliver

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Joerg Vogel Oliver H commented · Jun 30, 2017 at 06:12 PM

@Oliver H. The throughput time or staytime is possible. The Time is often computed by the statement: time()-getentrytime(item) at the sink and then the result goes into a table or tracked variable for more statistic results. The Process Time is a bit complicated, because the Processor can get into the state breakdown. If you record only the staytime of the item at the Processor, then the breakdown is included to this time. But in the Function ProcessTime you can store the return value into a tracked variable or table in combination with the processor name and then evaluate later.

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Answer 2 · 2017-06-29T11:46:47Z

Raja Sekaran answered Jun 29, '17 Nurul Ain bt Ismayudin I commented Aug 22, '21

Hi,

I have attached the sample model. In the attached model you can count the throughput time for each flowitem also it shows minimum, maximum and mean throughput time .

In the Sink, On Entry Trigger, I find the difference between Entry time of the item and creation time of item, then use global table to write those throughput time for each flow item.

I hope this will help you.

sample.fsm

sample.fsm (17.8 KiB)

· 10

Oliver H commented · Jun 30, 2017 at 02:31 PM

@Raja Sekaran

Thanks for your answer.

however, your sample file seems to be empty..

regards

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Raja Sekaran Oliver H commented · Jun 30, 2017 at 05:39 PM

Use version 17.1.2 to Open the model

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Marc B commented · Apr 25, 2018 at 02:34 PM

I have question to Raja's solution. I copy pasted that solution to my model (the entry trigger of the sink and the exit trigger of the entry aswell as the three global tables). Now I have the problem that the Table "mytable" gets not filled out. Did I missed something?

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Raja Sekaran Marc B commented · Apr 25, 2018 at 03:50 PM

@Marc B

Can you attach the model with changes you have made?

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Marc B Raja Sekaran commented · Apr 26, 2018 at 07:42 AM

problemdlz.fsm

Thank you Raja!

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problemdlz.fsm (88.2 KiB)

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Nurul Ain bt Ismayudin I commented · Aug 22, 2021 at 04:18 AM

hello. im quite new to this software. Im having trouble to understand on how you find the difference between Entry time of the item and creation time of item, then use global table to write those throughput time for each flow item. Is it possible for you to give a clearer instruction ? thank you in advance

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David Seo Nurul Ain bt Ismayudin I commented · Aug 22, 2021 at 12:28 PM

@Nurul Ain bt Ismayudin I

You need to upload this question as a separate question not linked.

The I will explain it in detail.

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Nurul Ain bt Ismayudin I David Seo commented · Aug 22, 2021 at 01:14 PM

I already posted the question. Thank you

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