Problem: rack is occupied. Is it possible to remove agents from a racksystem without using them in a flowchart?

Question

I am modeling order picking in anylogic: At the moment I create a population of agents and give them to the enter-block via an event. This block is connected with a rackstore block and puts the agents in the racksystem. In a statechart of a person (when the person arrives at the agent location), the agent is taken and put into another enterblock, which is just connected with a sink -> the agent is removed from the racksystem.

Problem: If I want to store agents in the racksystem again, the cells (where agents where before) are occupied. I think the reservation of the cell is not discarded. How can I solve the problem?

Or: Is there a better solution to store and/or remove the agents ? Maybe without using flowcharts at all?

Answer 1

Unless you're removing agents in racks via a RackPick block, you aren't actually removing them from the rack system (even if the agent is moving 'past' the RackStore block in the process flow). So your process would need to be something like:

• There is a Wait block following the RackStore (which holds them in the process until required).
• When the "person arrives at the agent location" (your trigger for removing the agent from the rack, though it's not clear what this means --- what is the "agent location" since it's in a rack?), you free them from the Wait block.
• The Wait block is followed by a RackPick block which will remove them from the rack.
• The removed agent carries on in whatever the follow-on flow is (which might just be a Sink in your case).

NB: Also, part of the functionality of RackStore and RackPick blocks is to use resource agents to move to the rack and deposit/retrieve the agent, so it's likely you don't need a "person agent" to be explicitly moving to the agent location (outside of these blocks), though that depends on the exact specification of what you want your model to do.