4-Way Shuttle Model – Logic, Inbound Setup & Multi-Shuttle Collision Control

baitoey_barry — Thu, 13 Nov 2025 05:13:48 GMT

Hi everyone,

I’m developing a 4-Way Shuttle model in FlexSim to test if the shuttle can achieve the target throughput based on my calculation file.

However, I’m still facing several issues and would really appreciate some advice:

The 4-Way Shuttle should not move through a location where a pallet is already placed.
Each time the shuttle changes direction, there should be a 12-second delay (Change of Direction Time).
I initially used AGV paths, but the shuttle occasionally stopped mid-way, so I switched to using Network Nodes to simulate a more realistic movement.
Need to define speed, acceleration/deceleration, and pickup/drop-off times (see attached table).
When testing the Inbound Process Flow, the slot was sometimes assigned to a location that already contained a pallet, which caused an error.
To resolve this, I created a custom inbound logic in my current model.
I’d also like to add a logic in the inbound process so that when a new pallet arrives, it is stored according to the same item (SKU) — meaning the same items are grouped or stored in the same area.
In Outbound Flow, the shuttle doesn’t pick up pallets, even when a task is created.
Planning to add multiple shuttles per level — looking for ways to prevent collisions or blocking, e.g., path reservation or priority rules.

I’ve attached my model file for reference.
Could anyone please suggest:

How to properly handle the shuttle’s direction change with delay?
How to set up the slot assignment logic to avoid pallet overlap and enable SKU-based storage?
Why the shuttle might not go to pick up pallets in the outbound process, and how to fix it?
Any other best practices for simulating 4-Way Shuttle systems using AGV or Network Node logic?

I’m still new to FlexSim modeling, so any advice, guidance, or example models would be greatly appreciated.

Thank you very much for your help!

Re: 4-Way Shuttle Model – Logic, Inbound Setup & Multi-Shuttle Collision Control

joerg_vogel_HsH — Fri, 14 Nov 2025 07:45:03 GMT

It looks like kiva. Then I suggest you look for answers and articles about this key phrase. Typically there are some tools involved:

A*star for a grid,

Agent system to control collisions of more agents going the same direction in an area,

baitoey_barry — Sun, 16 Nov 2025 13:44:40 GMT

Thank you so much for your advices.