Staytime for Processer longer than Process Time?

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victoria.davila asked Jul 25, '16 Matt Long commented Jul 25, '16

Staytime for Processer longer than Process Time?

In the model I have attached, I was looking into why the units were taking so long to complete. I am referencing a Global Table for my process times so i figured I wasn't referencing them correctly at first. However, for RXCabinet Step 1, I manually entered the Process Time versus referencing the Global Table. I added a Stay Time dashboard to capture how long a flow item was in the processor and running the model shows the item stayed in the processor longer than the manually inputted Process Time. I even looked at the Run Time to physically see a flow item move in and out of the first step and it looks like its in there longer than it should and I can't figure out why.

Software Version:

FlexSim 7.7.4

process times

assembly-rx-1.fsm (1.4 MiB)

· 1

Matt Long commented · Jul 25, 2016 at 04:26 PM

It looks like you're trying to reset your dashboard statistic objects manually in your OnEntry triggers of your processors. Not exactly sure why you want to do this, but if you must, it may be better to call reset on the stat objects rather than manually manipulating the bundles.

function_s(statObject, "reset")

0 ·

Answer 1 · 2016-07-25T16:04:23Z

Matt Long answered Jul 25, '16

The staytime of a processor is defined as the (time the item leaves the processor) - (time item enters processor). The staytime is not the same as the Process Time. Your model is calling stopobject on your processors and keeping the flowitem in the processor longer, increasing the staytime.

If you want to chart the Average Process Time per processor, the best way to do this would be to create a Tracked Variable label on each processor that is a Time Series type (see inittrackedvariable() command). Then use

setlabel(current, "processTime", processTime)

in the Process Time field. This will automatically update the average value on the tracked variable that can then be charted.

In your dashboard, change your Average Staytime option from the Statistics Tab to be a Custom and enter the following code:

getstat(label(i, "processTime"), "", STAT_AVERAGE)

(in the future you'll be able to chart these tracked variable labels directly without the need for custom code)

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