I'm a new AnyLogic user so hopefully this is a simple problem. I would like to use a block as to represent a storage area for items to be used in an assembly, I am using the delay block with delay time of 0, but maybe the queue block would be more appropriate? I have set up a model in which every X number of seconds a "truck" arrives and if the delay block contains less than a specified capacity of elements, the inject function is called to refill the block. This sort of works, but is seems that the agents are flowing through the delay block's out port and thus do not count toward its capacity (that makes sense to me...) resulting in my source blocks continuing to create agents when the system isn't ready for them. My delay block is followed by a "move by transporter" block which seems to be getting all of the delay blocks outputs immediately. There are only two transporters in my model and I am not sure why more than two agents can be accepted by the transporter block at a time. I set my transporter fleet to have a capacity of 2 but that did not solve the problem.
Any advice would be helpful! Perhaps a different approach is needed. My goal is to have an essentially unlimited pool of parts at the inlet of the factory, but only create agents when the downstream processes are able to pull them in. Thanks in advance!
Welcome to SOF :)
Best use a "Wait" block here:
Let your trucks dump stuff into "Wait" whenever they arrive. Your downstream block can now pull them when they are ready using myWaitBlock.free(someAgent for as many agents as they want to pull from it.
Similarly, you can use a Delay with infinite capacity and set its type to "Until stopDelay() is called". Then similarly as the "Wait" block, you call myDelayBlock.stopDelay(someAgent) when you want.
Another option: Use a hold-block in front of a normal (infinite) queue and unblock it when ready: myHoldBlock.unBlock(numToLetThrough) --> probably the easiest
PS: Please also check how to ask good questions here on SOF, yours is very long, much easier to understand with some screenshots :) --> https://stackoverflow.com/help/how-to-ask
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I am building a model where at any point in time if any agent is in system beyond threshold it has to go to Sink block. Is it possible to do it based on Agent time in system ?
If agents spent 180 days and beyond I want to send it to write-off block
what you need to do first is to create an enter block that connects to your sink block
With that done, most of the blocks have a remove method associated, so you can do this, with any agent a:
a.currentBlock().remove(a);
enter.take(a);
Nevertheless, this is not good practice in my opinion, removing an agent from any block at any time will almost certainly mess up your flow logic in some way...
Edited Version:
I'm actually modelling an airport check-in terminal. It works fine so far, but additional I'm still trying to implement a function, that allows my pedestrians not to enter the service-queue if the queue time exceeds a preselected value (e.g. already 15 Passengers in the queue) and therefore walks to some kind of backup Service that opens during this busy times.
Here is my approach:
Variable QueueSize returns permanently the actual Number of Passengers in the Queue.
Every time a ped enters the pedservice block CheckInEco, the function waitingTime() starts:
QueueSize = CheckInEco.size();
if (QueueSize > 15) CheckInEco.cancel(ped)
So, as soon as there are more than 15 Agents in the queue, number 16 should bypass and move to an alternate ServiceBlock, which I would connect to the ccl Port of the CheckInEco Service. But when building the model, I get this message: ped cannot be resolved to a variable?
According to Anylogic Help, it should be possible to use this cancel - call, but I'm not really experienced with it.. Maybe, someone can help me out?
You can simply use a select output block to prevent pedestrians from going into the service block if there are more than 16 pedestrians already in.
Your original question had to do with waiting time, you should follow the exact same approach. But with waiting time it gets more complicated since you don't want to take the average waiting time from the start of the simulation.... so you need to decide if you want to take the last 10 minutes, 1 hour etc and do you want to include the current waiting time of agents in the queue. Since this is the the questions anymore I am not going to add it here, perhaps ask a new question if this is still the case.
im creating some paths with the process modeling library. The trucks shall stop in series when waiting for the "go" signal to go on.
At the moment the trucks are waiting "within" each other.
How to tell the trucks to recognize not the stopnode only but also the hitbox of the truck which arrived before him?
Thanks in advance
Chris
The trucks shall stop in series when waiting for the "go" signal to go on.
At the moment the trucks are waiting "within" each other. [...]
How to tell the trucks to recognize not the stopnode only but also the
hitbox of the truck which arrived before him?
AnyLogic allows for agents to queue along a path (from an animation perspective) whilst in a Queue block. So don't make them move to the stop-node (which I assume you are doing explicitly): make them (from a process point-of-view) go into a Queue which is animated via the path from the stop node 'backwards'. (This is the "Agent location" setting of the Queue block.) How you hold them in the queue and release them when they need to depends on the nature of your model; e.g.,
Use a Hold block following the Queue (if it makes sense to release them all at once)
Use a 'dangling' Queue block which you pull agents out of programmatically (e.g., via its removeFirst function) and then add them somewhere else in the process via an Enter block.
Use a Seize block (which has a built-in Queue you can set the location of) with the resource seized representing the 'token' you need to proceed.
NB: From the process perspective, they are in a Queue which happens to be animated as queueing along a path. This isn't exactly the same as modelling the 'spatial reality' of being in a queue: see this question.
Simple solution is to turn your truck agents into Transporters from the Material-handling library. They have build-in collision avoidance.
However, this can slow large models so you may want to convert them only when you need collision avoidance and then convert back to "simple" Truck agents again.
Else, you need to build your own additional stop-nodes and code spatial queuing manually. Possible but not straight forward
I am modelling earthmoving operation. Every trench agent seize two transporters, one excavator, and one truck. When truck is released it will do some other job before been seized again by the same trench. So this process repeat until the trench will be empty.
The process is occuring for two three times without any problem but after two three times the trench agent is not go out of the seizeTransporter block (the one that seize truck). I have a delay block after the seizeTransporter block and it use Maximum Capacity. So it should not be a problem and it should not prevent the seizeTransporter block out port to push the trench out.
I noticed this is hapenning when the truck stop to resolve a collision. It looks like the collision cannot be resolved and the truck stay where it is for ever. :))
I have tried so many things that could solve this problem but none of them works.
There is an option in the material-handling library TransporterControl element to override transporter conflicts after some time. Maybe reduce the default timeout of 10 model time units, see below:
I'm trying to emulate what QUEST does when a buffer is queried for a certain Part. In there if the part is not in the buffer the request is left pending and if a Part arrives to the buffer it's released to the machine requesting it. I have also seen this behavior in SimPy which is another DES engine.
I can't seem to find a simple way to do this in AL. The queue block has the following methods:
release(agent): Will return false and forget about the request if there's not an agent as the one specified
remove(agent): Will return null if there's no agent in the queue
So those methods won't do what I want...
It gets a little more complicated as the queue contains agents with parameters and I want to request a specific set of parameters (let's say the agents have a number parameter that can go from 1 to 3 and I'm only interested in agents in the queue if this parameter has the value 2).
Also there's a series of agents pulling this agents from the queue simultaneously and I'd like a priority to be set (let's say FIFO)
so there's a couple things that I've tried and have lead me nowhere:
Using a seize block instead of queue and adding the agents to the embedded queue in the seize block. -> I can't find the proper method to seize from the buffer in a different way from a buffer block (so I moved to option 2) but seize does have a promising customize resource choice that could help with the parameter down-selection
Using a seize block and storing the agents in a pool as resources. issues with dynamic creation of resources, seizing the appropriate one etc...
Creating a queue of requests that have returned null from a queue. This sounds like an overkill but I'll look into it
All of those appear to be a bit complex for such a simple thing in other softwares for simulation so I'm wondering if I'm missing something or if someone has come across this issue before
Suggestion 1: may it helps you to store the agents in the queue in a collection (or different collections, according to the parameter settings). Events: "on enter" and "on exit"
Suggestion 2: may the Wait - block helps you here?