I want to assign priority to my agents and then queue them based on that. I have an agent Container which has two parameters carrier (which can be either Truck or Train) & priority (which is to be assigned with some value). 50% of agents where carrier=Truck and 50% of agents where carrier=Train should be assigned priority 1 and rest should be zero. How can I do that?
This is my model. []. I want to move the above mentioned agents from storage1 to rackPick block on priority.
Thanks in advance.
This can be achieved by creating an integer 'priority' field in the agent and then setting it to 0 or 1 based on random(0.5) value in the on at exit action of the originating Source and then checking that field in the Queue to get priority. It won't be exactly 50% but pretty close for a large enough number of agent.
Related
I have two variables in agent
handicap = RandonTrue(0.3)
priority.
The priority variable value set in source exit based on wither agent is handicap or not, as shown in the image below.
Now in the queue I set Queuing to priority base and set agent priority to agent.priority . Shown in image below.
Note: Queue capacity is set to 10.
Now when I run the model and 10 agents enter I the queue, according to the priority handicap agents should be on the top of the queue but that is not happening. shown in the image below.
When the agents enter the delay after the queue, I also print their priorities on the console. The result is still the same, no priority is followed.
In the above image it is clear that they are not sorted based on priority.
Why priority queue is not working?
Moreover, I also changed the Queuing to LIFO, queue showed the same result, showing zero effect on agents.
this happens because contrary to the intuitive idea that events happen in the order you see, they don't... Things occur in the following order:
agent is created with the default value for the priority value
on at exit action is executed
the queue priority value is checked for the queue
the on exit action is executed
So from the point of view of the queue, the priority for all agents is the same
Solution
Instead of setting the priority value "on exit" do it on the "on at exit" action of the source block
I currently have 2 different source blocks, 1 that sources agents for one half of the day, the other for the other half. Both converge into the same starting point of the model. I am only using 2 different sources to help simulate 2 different halves of the day.
I also have a resourcePool that increases in capacity from 1 to 2 at time() == 150. How can I ensure that the 1st resource unit that starts the day interacts only with those agents coming from source1, and the 2nd resource unit that arrives at time 150 only interacts with those agents coming from source2? Agents from both sources go through the same seize blocks that seize 1 unit each of 2 different resources at the same time.
There is a short overlap in which both resource units are working, so I want to ensure that one is not interacting with the other's agents.
You need to make use of the resource choice option inside a size block.
To do this start by having a new agent that will represent the resources inside your resource pool and give it a variable that you can use for assigning what source agents it will take. e.g. have an int variable sourceNumber
Now when you increase the number of resources in the resource pool from 1 to 2, you assign the source number of the second resource to 2.
resourcePool.set_capacity(2);
int counter = 0;
for (MyResource r:resourcePool) {
r.sourceNumber = counter;
}
If the agents that need to seize the resource all use the same seize blocks it is perhaps best to make a custom agent and send the seize block from which they came to the agent.
Then inside the source the resource choice field van be used to dictate the correct resource to use
I know the basics of AnyLogic/Process Modeling Library and am about to teach simulation of basic queues with AnyLogic, transitioning from Simul8 that I 've used for many years.
I have agents of two types, 1 and 2, sent to respective queues 1 and 2, which then feed a single "service" point, so that type 1 takes higher priority (that is, whenever service is ready to pull work, it pulls from queue 1 if it is non-empty, regardless of the size of queue 2). How to capture this as simply as possible?
Having seen the reference pages for a Queue object, my preliminary (unworked) idea is to use a single queue, and control agent priority by the Queue.QUEUING_PRIORITY- Priority-based" option.
For comparison, a solution in the Simul8 software is: set "service" routing-in discipline to "priority"; and assign different priorities to the two queues.
Yes you are right you cant use two queues as the pull from the queues will be done in a round robin fashion. See the screenshot below from the AnyLogic training textbook
You should use queueing in a single queue and you can have either a single parameterised source or two.
See example below
I have 2 sources and at each of them, I set the priority to a local variable inside my agent. Agents from source 1's variable is set to 1 and the from source set to 0.
Then inside the queue, I set the priority so that the agents from source 1 is always in front.
I am using a priority based queue to pick agents from a pallet rack. Priority of agents can be 0 or 1. If there are 10 agents in palletRack, I want to pick all the agents having priority=1 first. My problem in the current flowchart is: Agents with priority=0 are pickup up before agents with priority=1. May be because the agents enter & leave the Queue block one by one, multiple agents aren't present in the Queue block at the same time so that they can be sorted. How to resolve this?
put a hold block between queueStorage2 and pickFromStorage1 and on the on enter action of queueStorage2, you check if all your agents are there, and if they are (with whatever condition you need to check to be sure everything is there) you unblock the hold with hold.unblock();
I have a not so typical scenario for which I am not sure how to proceed:
There are two stations located at two different locations.
Both stations require the same resource.
The resource moves from station to station once released. So it keeps going from station 1 to station 2 to station 1, etc. until it is seized again. This is modeled by adding a link from the resource process port of the release block. So it is not completely released unless a condition applies. The condition is that there are agents waiting in the queue of the seize block of that same resource. So it should keep moving until it is needed again. The tricky part is that there are two seize blocks for that resource, one for each station. It is possible that agents are ready and waiting in the resource's seize element at both stations. I am adding an image of the resource's process at release. So at "selectOuput4" it checks whether station 1's seize element has agents waiting, if so, the resource is released and can be seized. Otherwise, it moves to station 2 and checks the same but for station 2.
My concern is that there might be a situation where both stations have agents waiting in their respective seize blocks. How can I make sure the resource will be seized by station 1's seize element and not station 2's, and vice versa. Is there a way to control where the resource is going in a case where two seize elements are waiting for it? Or is it always random?
I apologize for the long post, and I hope I managed to deliver my idea properly.
First, I think your design is a bit weird because you keep the resource always seized.
What I would do is first have a statechart in the resource that controls the resource movement from one place to the next so you have more control over it. The statechart would be used to move your resource ONLY when it's not seized. This will allow a case in which your resource is moving from station 1 to station 2 but something comes to station 1 queue and the resource can immediately react and come back to station 1 before it reaches station 2 (if you think it would be a good idea to do that)
The second is that the seize block defines the priority for a task when the agent arrives to the seize block, and your situation requires changing that priority dynamically, which can't be done as far as I know, so the wait block before the seize block is unfortunately a good option.