Conditional elevator

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Julio R asked Nov 19, '19 Benjamin W2 commented Dec 20, '19

Conditional elevator

Hello,

I have a model where operators use an elevator bank to get to a second level. I have used two grids with Astar to do this and it works as intended.

The problem is that I am using a transporter to put objects in some high racks, but it does it without using the elevator. Still I want to use Astar to help navigate the trasnporters between other racks. I think something similar to the conditional bridge of the Astar.

Here there is a simplified example, I want the operator to use the elevator and the transporter to place on the rack without using the elevator but using Astar to avoid colisions.

asdf.fsm

I have been tying different things and I discovered that if I have a Astar grid higher than cero without an elevator the transporter wont know how to deliver . Here there is a small example:

prueba-error-astar.fsm

Software Version:

FlexSim 19.1.2

astar elevator grid

asdf.fsm (45.2 KiB)

prueba-error-astar.fsm (31.4 KiB)

Answer 1 · 2019-11-26T21:07:49Z

tannerp answered Nov 26, '19 Benjamin W2 commented Dec 20, '19

Hi @Julio R,

It took me a minute to figure this out, but if you just exchange the Transporter's Unload activity for a Move Object activity, then the Transporter will not move in the elevator when it is dropping off at the rack.

I think this is the behavior you are hoping for. Let me know what feedback you have.

asdfg.fsm

move-instead-of-unload.png (25.5 KiB)

asdfg.fsm (44.2 KiB)

· 3

Julio R commented · Nov 26, 2019 at 10:09 PM

Thank you, this almost solves it.

My only problem with this solution is that for racks with a considerable size the transporter doesn´t go exactly to the bay it needs, and with enough travels the difference in travel distances will be big enough to affect the statistics results.

I have though about traveling to dummy objects in front of each bays but for a big distribution center there are too many.

Other solution could be traveling to coordinates based on the location of the rack, number of bay and size of bays, but to implement this for all racks it needs to take into account the rotation to make the calculation, so I was looking for a simpler solution.

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tannerp Julio R commented · Dec 16, 2019 at 05:38 PM

Hi @Julio R,

I apologize for the delayed response. I thought about how this could work using a visual and it gets rather complex, but like you mentioned, we don't want to have inaccurate statistics because of travel time variations.

Here are my thoughts for a solution. Instead of traveling to a specific location and then using the Move Object activity, you can use a Delay activity that looks up a delay time in a table based on the location in the rack. You could do this two ways:

1) The Delay time can be set by looking up the item's location in the rack in a Global Table to get the approximate travel time.

2) The Delay time could also be set by getting the item's location and running a function in the Delay activity that would change the time based on rack number or something similar (i.e. Delay Time = Bay# * 5 seconds)

This may not have the strongest visuals, but it will achieve more accurate statistics, I think. Hopefully this helps.

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Benjamin W2 commented · Dec 20, 2019 at 06:26 PM

Hi @Julio R,

Did Tanner's answer solve your problem? If so, please click accept. If not, how else can we help?

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