Good day
I'm a new user trying to find my with Anylogic.
Any help with the following question will be appreciated.
Is it possible to start a model with initial values/quantities given to certain blocks/sections in a model? In other words not have the model start from 0 but from the values given.
You can run a "warmup" period manually and save that as a model snapshot. In future runs, you can start off from that snapshot by loading it. See the help on model snapshots
This is the general problem of model initialisation (e.g., if you're modelling a manufacturing facility, you may want the run to start with the facility at the state it would be at on 9am next Monday morning). There is no generic answer: what initialisation you need is 100% model-dependent (as is how easy/hard this is).
In particular, process models make this difficult because entities (agents) are expected to have flowed through the process up to the point they 'start' in. You can use things like extra initialisation-only Source/Enter blocks to 'inject' agents into the appropriate process points, but in most models it's not this easy: you will have all kinds of model state that needs to be made consistent with this (e.g., the agents flowing through the process might have attributes which have changed based on what's happened to them so far, so this would have to be made consistent).
That's why warm-up periods (letting the model run 'from empty' for a period until its state is qualitatively what you want as your starting point) is a common approach. Model snapshots can help you here (see Ben's answer) but they're not the only way of doing it. (You can also just 'reset' all your metrics/output gathering at the point when you determine the warm-up period has ended --- i.e., you are effectively establishing a new 'time zero' --- but, again, exactly what you need to do is 100% model dependent.)
Related
I am a newbie to anylogic simulations. In my project, I want to take out queue size at every time step from a service block and create a dataset. Similarly, I also want to take out the mean queue size from the same after every replication and create a dataset of that as well. Can anyone help me with how to do it?
Welcome to SOF and AnyLogic. Best post separate issues for separate questions, see this intro to SOF for AnyLogic users.
But for now:
I want to take out queue size at every time step from a service block and create a dataset.
Use a cyclic event that calls myDataSet.add(myServiceBlock.queue.size())
I also want to take out the mean queue size from the same after every replication and create a dataset of that as well.
In your experiment, add a DataSet myMeanResults. In the "On Simulation end" code box of your experiment, call myMeanResults.add(root.myDataSet.getYMean())
Make sure your Datasets can keep enough values!
Also, always check the AnyLogic help and example models. Very often, these basics are covered there already. Else, tell us what you already tried :)
I am trying to simulate a manufacturing assembly process, where material items are processed following an unique line. In the quality control stations, when a failure is detected, the object is sent to the repair area (by a truckpallet) and, when it is repaired, the same resource takes it and puts it at the start of the line. Until this point, I already programmed it.
The problem is the following: when it is a repaired object, is has to follow the same conveyor but with no stops in the stations. The object must enter a station and leave it, with no delays (as the works related with the stations have already been made).
I thought the best would be to consider the difference (repaired vs. not repaired) in the Agent, but then I can't work with it in the Main agent... I have also tried alternative solutions, for example defining variables in each station 1 and consider that in the stations delays and in the following station:
triangular( 109.1*delay_bec, delaytime_bec*delay_bec, 307.6*delay_bec)
Actions - in finished process:
if(delay_bec==0){
delay_headers=0;
delay_bec=1;}
But nothing worked... Any help?
I thought the best would be to consider the difference (repaired vs. not repaired) in the Agent, but then I can't work with it in the Main agent...
This is actually the correct approach. You need to create a custom agent type, give in a boolean variable isRepaired (or similar) and then in the delay you can dynamically adjust the duration using that characteristic:
agent.isRepaired ? 0. : 100
This will delay normal agents by 100 time units and repaired agents not at all.
Obviously, you must make sure that the agents flowing through the flow blocks are of your custom agent type (see the help how to do that)
I am using Anylogic for a simulation-modeling class, and I am not anylogic or coding smart. My last and only coding class was MatLab based about 16 yrs ago. I have a few questions about how to implement modeling concepts in a discrete model with anylogic.
How can I add/inject agents directly into a queue downstream from a source? I have tried adding an additional source to use the “Calls of inject() function,” but I am not sure how to implement it after selecting it ( example: what do I do after selecting the Calls of inject() function). I have the new source feeding directly into the queue where I want the inject.
How can I set the release of an agent to a defined schedule instead of a rate? Currently, I have my working model set to interarrival time. But I would like to set the agent release to a defined schedule. (example: agent-1 released at 120 seconds, agent-2 released at 150 seconds, agent-3 released at 270 seconds)
Any help would be greatly appreciated, especially if it can be written in a “explain to me like I am 5yrs old” format.
Question 1:
If you have a source connected directly to a queue, then when you call source.inject() an agent will be created at the source block and go to the queue. If you have 1 source with multiple possible destinations, then you will have to use select output blocks and some criteria to go from the source to the desired queue.
Since you mentioned not being a strong programmer, this probably wouldn't be for you, but I often find myself creating agents via add_population and then just adding them to an ArrayList until I am ready to pull them into the DES flow. Really, there are near infinite ways to control agent flow within AnyLogic.
Question 2:
Option a: Arrivals by "Arrival Table in Database" You can link an AnyLogic database table to Excel, and then the source block will just have an agent arrive based on that table.
Option b: Arrival Schedule - you could set this up manually within the development environment or load your schedule from a database. I prefer option a over option b given your brief description.
Option c: Read in data to variable and then write code to release based on next arrival time. 1,000s of ways to do this, but one example could be a list of doubles (your arrival times), set an event to delay until next arrival, call inject function, remove that arrival from the list. I think option a would be best for you, but given that AnyLogic allows you to add java code, there are no limits to how sophisticated you could make your arrival logic.
For 2) You could also use an event or a dynamic event. The action could be source.inject(1); and you can schedule them to your preferences with variables. Just be vigilant that you re-start the events if necessary.
There is a demo-model from AnyLogic for dynamic events.
I am modeling ticket system with various SLA. The model must contain several service blocks with different reaction time ( from 2 to 32 hours). In the service block only working hours should be taken into account. So in the service block timeout should stop when non-workong hours and on the weekend. Could you please kindly tell me how i can realize it?
Thank you very much in advance!
I can think of two answers, one simplified but works in many cases, the other more advanced and probably more accurate:
Simplified approach: I would set the model in hours and keep everything running as is without any stop. So, at the end of the simulation, if the total time is 100 hours and you know that you have 8 hours/day with 5 days/week, then you'd know the total duration is 2.5 weeks. Of course, this might have limitations or might become more complex later on if you want day-specific actions (e.g. you want to differentiate between Monday, Tuesday, etc.)
Advanced more accurate approach: Create resources whose capacities are defined by schedule and assigned them to your services. Create a schedule and specify the working hours in that schedule. Check the below link to learn more about schedules. I call this the more advanced approach because you need to make sure the schedule is defined correctly and make sure all elements in the model are properly controlled (e.g. non-service blocks such as source, delays, etc.).
https://help.anylogic.com/topic/com.anylogic.help/html/data/schedule.html?resultof=%22%73%63%68%65%64%75%6c%65%73%22%20%22%73%63%68%65%64%75%6c%22%20
I personally would use the first approach if the model is rather simple and modeling working hours is enough for analysis. Otherwise, I'd go for option 2.
Finally, another option I'd like to highlight is the "suspend/resume" functions. I am only adding this because you asked "how to stop timeout". So these functions specifically stop and resume timeout. But you'll need to define the times at which they are executed (through an event for example).
I'm modeling a hospital ward. I am experiencing this error:
"Model logic error:root.delay7:
An agent was not able to leave the port root.delay7.out at time 8.302 / date Nov 3, 2020, 8:18:05 AM (current model time is 8.311).
Consider increasing capacities and/or throughputs of the subsequent object(s) or using PULL protocol"
I know that before a hold I have to put a queue block, but in the path to follow the patient has already been inserted!
If I insert more queue blocks they slow down the process, because once the patient enters the queue block he is not released immediately!
Why does this error occur? How can I fix it?
I attach the picture, the red circle indicates the point where the flow is blocked.
it's simple...
the hold is a door, and if it's blocked, the door is closed
If you try to push a cat through a closed door, the universe will tell you that the cat just cannot do that, either by you killing the cat, or the cat killing you.
AnyLogic is doing the same thing here... It's not a requirement to put a queue before the hold block, but you need to think this from a more realistic way.
If your cat is in the delay block, and now you want to move the cat out of the delay block, but the door is closed, the question is... what do you want to do with the cat?
The answer to that question, will bring you an answer to your model... tell the model what you want to do with the agent after the delay block, if the hold is blocked... do you even need a hold block there? Think again on what you are trying to do, and revise your model based on your concept.
People tend to forget that with a model you are trying to represent reality... do that... investigate what reality looks like, and make a model that maps with that reality