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Non-blocking path with workers in both directions?


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Hi All,


At the moment, I'm trying to model a warehouse. This warehouse consists of aisles: long sections of bi-directional paths, intermitted by basic nodes that represent picking locations. Workers walk through these aisles to pick orders. See also the attachment: the nodes are not visible but there are 20 nodes in every aisle.

However, the bi-directional path does not enable workers to walk in two directions. It is possible for workers to encouter each other while traversing the aisle in opposite direction. This will create a blocking situation.

I tried to solve it by using the 'Travel' step, such that the workers travel through 'free space' within a certain width around the warehouse network (setting 'avoind collision' to 'true). The problem however still exists.

Is there a neat solution for this? It is a possibility to introduce all sort of extra bypass paths. However, this will make the model more complex and introduces walked distance biases. One of the purposes of this model is to compare theoretical picking times (based on walking straight through the aisle) with simulation. Adding extra bypass paths would violate therefore the purpose of the model.


Thanks in advance for your suggestions!


Wouter

1967769821_overviewwarehouse.thumb.png.a1f7b94b8a229d09737a07b320c910aa.png

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Thanks for your reply! I'm not sure whether sharing the model is the easiest way to do this. There is a lot of logic outside of this path walking behavior incorporated in the model that will not make it easy to understand it right away ;) What would you specifically like to see?

Regarding the picture: you see a top-view of a warehouse: the straight lines are the aisles (bi-directional paths) and the blue 'dots' on the isles are the workers (you see three of them blocked in the upper left part of the screen). In between the aisles you see drawings of cabinets and pallets without any meaning in the model. The long straight aisles are actually multiple paths connected by basic nodes (not visible in the picture). The workers are being told to move to one of these nodes by a 'move' step to simulate the picking of a specific product in the warehouse. After the move request, workers use the ' travel' step for physical movement. They use the warehouse path network as a guidance for their walk (path width set to 0.1m for example).

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The primary movement constraint that Simio supplies for you is the various types of Links. Simio provides the option to prevent entities from running into each other. There are a number of SimBits to help understand the options, including Path Selection Rule.


If you use bidirectional paths, it is often easy to get into deadlocking situations. Ways to avoid this include limit path capacity to 1, or perhaps having zones with limited capacity. Or instead consider a pair of opposing unidirectional paths.

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