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How do you define a new state variable for an entity type? I mean here the things that arrive and travel through he model (they would be temporary entities in SIMSCRIPT II.5, transactions in GPSS/H, workpieces in Simul_. I have consulted the online help, and gone through the SimBits that looked as if they should be relevant, but cannot find an answer anywhere. I am attempting the embarrassingly simple task of randomly assigning a priority, 1..3, to an entity on arrival into the model, and later having them queue FIFO within priority class for service. As I do not need dynamic priority I expect a parameter would do instead of a state, but either way I cannot find how to perform the simple task of defining a field for an entity class. Once that is done I expect assigning to it should be easy. All the best, John.

If you have an Entity object name for each exam type, for example, you could first have a table that contains a entity object reference type column that is 'Set Column as Key' with another column in same table (expression likely) to store the processing distribution associated with each entity type. Then, in another table, add a date/time column to use as your arrival table, with a second column that is a 'Foreign Key' column that references table 1 entity key column. Then you can have each separate arrival reference one of the entity types specified.

I am using a table with two columns, first is the arrival time of the entity and the second is the property. The first column is used as the arrival times (one entity per row). In other words I should set the row for each entity which indicated the arrival time and the property. But I could not find a way to do that. I can use the first column to create the entities using "Arrival table" in the source. But then I can not make sure the specific row which was used to create that entity is assigned to it. If I know how to do that, then I know how to set the property using state definition. Thanks

I cannot open files with academic license but can help with the problem: First of all, do not set the interarrival time to 0, that is dangerous, use entities per arrival to have more than one at the same time. If you set a row on Before Creating Entities, you will get the same row for all entities per arrival. Instead, you should assign jobs On Created Entity, once you already have them. Then you can assign the values to entity states and go forward with processing. For the target, make a queue (storage element) minimizing the processing time and always take the first element.

You could also just use the DayOfWeek function to set the entities per arrival to 0 on Sunday (day 1) or Saturday (day 7):

The Standard Library Source object will always create "Entities Per Arrival" number of entities of "Entity Type". One option is to subclass or copy the Source object and change that behavior. Another option is: --Decrease your interarrival time so they arrive 5x as fast, and set your entities per arrival to 1. --Use a Combiner (or perhaps the object described here: http://www.simio.com/forums/viewtopic.php?f=36&t=1024) to combine 5 entities together to sync them. --Then immediately Separate them so they can flow independently, if that is what you want.

When you run your model an instance of each vehicle type begins to travel around (according to the sequence you defined). At each arrival time you defined, a new instance of vehicle is created accordingly and then they begin to travel around as well. In summary, at startup one instance of each vehicle type has to be created. Afterwards, the second instance of each vehicle type is created according to the arrival table. I revised the model and attached. 4 vehicles on time %28trying%29.spfx

HI I am a fairly new user and please forgive my confusion. I am working on a project where there are different vehicles coming on different times throughout the night. (for resurfacing etc) I created Arrival table correctly, entered date time values accordingly. The quantity of each vehicle type required is 1. Routing Logic is defined too. I used a Token process as well to guide source. BUT for some reason, when I run the model, all vehicles leave the source at once and then 1st vehicle type keep coming after every hour. BTW it works well if I use no Nodes and simple Source to Sink Path, However, when there are nodes, it mess up and all vehicles leave source at once. Can anyone please tell me what am I doing wrong ? Huge thanks in advance P.S I have attached my current model as well 4 vehicles on time (trying).spfx

Hi Willem thanks for replying. Yes I have made and used an arrival table, the problem is all my vehicles leave the source at once i.e. not following the arrival times for some reason.

Try arrival tables, might be the easiest solution.

One easy way to do this would be to create a second 'Real' type column within the first table, Table1, named Proc (like the Table2 column) which includes the minutes for processing corresponding to each arrival time. Then, within the Server Processing Time property, use Table1.Proc (newly created column). When the entity is first created using the Table1.Arrival column for the arrival time, that entity has then an associated row in that table. Therefore, when you reference Table1.Proc, it will use that entity's corresponding row. Alternatively, to use the two separate tables, you would need to first set the entity row reference for Table2 (perhaps using a SetRow step within a process based on the entity as it enters, such as SetRow - Table Name = Table2, Row Number = Source1.EntityArrivals.EventCount, which is the 'count' of entities as they are created).

Hi there. My model is based on a vehicle assembly line and when running experiments I have kept all factors constant except for part entities per arrival. Up until a certain number (9 entities per arrival) the experiments run in a few minutes (with 10 replications) however anything greater than that causes the experiments to take hours to run just 1 replication. No warnings have come up for too many entities present in the system or anything like that. What could be the possible causes for this?

Hello! I am modeling a wash station that takes 30 minutes for the first piece, and an additional 5 for each piece after that(so a batch of 3 would take 40 minutes, a batch of 6 would take 55 minutes, and so on) but I'm having some trouble putting this into a processing time. The added problem is that the number of entities changes. Currently I'm using a source that produces one "shipment" a day with "Entities per arrival" set as "random.triangular(3,13,19)" which is working fine for my quantity, but I don't know how to relate that into the processing time of the next workstation. Thanks!

Thank you for your quick reply! Yes, I am using workstations. Could you tell me more about this resource reservation? That's a new one for me. And I just had another question. I am modeling a wash station that takes 30 minutes for the first piece, and an additional 5 for each piece after that(so a batch of 3 would take 40 minutes, a batch of 6 would take 55 minutes, and so on) but I'm having some trouble putting this into a processing time. The added problem is that the number of entities changes. Currently I'm using a source that produces one "shipment" a day with "Entities per arrival" set as "random.triangular(3,13,19)" which is working fine for my quantity, but I don't know how to relate that into the processing time of the next workstation.

Worker returns to Server1 because a new entity has arrived at server1 and seized the worker before the first entity could get to server3 to seize it. There are actually some new features in the latest release (sprint 122) which make it easier to reserve a worker for later and prevent other objects from seizing it. From your description it sounds as though you only expected to have one entity processing at a time within the 3 servers. If that is true, then you must adjust your logic to make that so. Possibly use the OnEvent arrival model on source1 and only create a new entity each time one exits server3.

Sumanth - You have quite a few different ways to go about collecting these interval based statistics, the first few that come to mind include: (With Enterprise Edition) setup a daily timer and trigger a process to write the statistic to a output table, then reset the statistic Setup a tally statistic and a daily timer and trigger a process to tally the statistic, then reset the original statistic Setup a array and a daily timer and trigger a process to capture the statistic in the array, then reset the original statistic As you can see, in all cases have some statistic that can be cleared on the interval after capturing its data in either a output table, tally statistic or array. Let us know if we can be of any help with your healthcare model -- we've done quite a few of these with various levels of detail depending on the question at hand. Sincerely, Martin

I constructed a simple model with a single server where I used a rate table for arrivals. The server block capacity was fixed at 2. When I run this model by hand, I see that maximum holding time for the input buffer of the server is just about 24 minutes every time (but the same exact number), just as it would be if the arrival rate was constant throughout a 24-hour period. However, when I run an experiment where I defined the Server1.InputBuffer.Contents.MaximumTimeWaiting as the response variable, the result is 40 minutes for the scenario where the server capacity of 2 is 40 minutes.(I am using version 5.91) I am wondering 1) if I am confusing two different quantities (maybe the maximum holding time result is averaged by dividing by capacity, but that would be a bug, because the capacity should have no effect on the input buffer) or 2) if the randomization seed is the same for every run that I do by hand, which must be the case, because when I reduce the required replication count to 1 for the experiment, I get the same exact result for the single run that I do by hand. If that is the true reason, then I must ask where to change the randomization seed for every run.

I want to monitor the total inventory of all servers. Lets say only InputBuffer of all Servers is enough. So i want to see how much buffer i need/have when i have random server failures, repair times and changing processing times (later i also want to add random arrival times). So therefore i was focusing on the HourlyStatistic Simbit which i think is really helpful to get started with the Plots. Because i have many servers i did like in Simbit recommended and created a Server Object. With the intention that i can monitor the inventory of all servers together without doing the assignments for every single server. And then i created some experiments with the total inventory as a response value. I add a small model where u can see my experiments. So it worked but i can only see the inventory for each server. But i want the combined inventory. Goal of my model: Analyzing / Monitoring actual inventory level of all servers while changing failure rates, repair time and processing time. Problems: --> How can i monitor the inventory of all servers together, in the experiments as well as in the plots? I thought i could do that with the server object. --> Can i change a standard library server to my created server object without deleting already created servers and entering everything again? Thank you very much again, that forum helped me already a lot.I hope i could describe my problem clearly. (The model i added consists of 2 servers, 2 sinks, 2 sources. The vehicle transports the entities to the servers. Servers have random failure, repair and processing time. Vehicle drives always the same fixed tour and delivers specific entity to specific server.) InventoryMonitoring.spfx

Schedules are associated with resources. The standard library Source object does not have a resource because there was no obvious purpose to it. You could certainly create your own implementation of Source that has a resource and lets that resource follow a schedule. Why are you looking to have Source follow a schedule? If it is to control entity creation, there are several obvious ways (Arrival Mode) and less-obvious ways (creative use of more advanced Tables, Functions, and Schedules) of doing that.

Hi, I tried to set up this solution for a particular step in my project : I have a source having an arrival table built as stated above : each entry of the table is a realState (unit type: Time in seconds). I tried to update state values during simulation run but it seems that the source or data table stores initial values somewhere in memory and doesn't take into account any modification during simulation run. Does anybody noticed the same behavior as me? Did I do something wrong ? Thanks !

David - Glad to see you are getting your hands dirty with Simio. The problem in your model is that you have the Source 2 set to create between 1 and 4 entities per arrival. Your combiner is set to Batch Qty of 4. So if say only 3 entities are created in Source 2, they (and their matching parent) will never pass through the combiner, since they are waiting for the 4th entity. As a solution I would suggest having either the parent (preferred) or the members carry a reference value to how many batch members are expected. Then use that in the Batch Qty field on the combiner, such that the combiner works with any 1, 2, 3, or 4 batch member sizes. Sincerely, Martin

Use the Standard Library Source object. Select and arrival Model of Arrival Table. Look at the help on that topic for more information. I believe there is a SimBit illustrating what you want to do.

You might build a model like this: Source -> ItemToFlowConverter -> the flow line Where the Source object is the Standard Library Source for creating discrete entity arrivals. So, use a Source to create discrete entities (of possibly varying entity types) from table data. Then have each discrete entity go into an ItemToFlowConverter to be converted into a specified quantity of flow, by specifying the 'Flow Quantity Per Item' property however you like (sounds like that will possibly be a value also coming from table data that was used to define the entity's type). The FlowSource is currently easiest to use as an infinite flow supply of some flow type. You can of course open and close the 'Output' flow regulator (e.g., Assign Output@MyFlowSourceName.FlowRegulator.CurrentMaximumFlowRate = 0 to close the output valve of the flow source). However, if you have a situation with discrete arrivals of flow quantities where each arrival has some entity type and some volume or weight quantity, I think using a Source -> ItemToFlowConverter combination is probably the best way to go.

Ok. I've been looking for replies almost daily, working on a different side... Now, coming back.. Hopefully an easier question. How can I reset the FlowSource after it has generated a predefined volume of an entity? So, I have a table with sequence of volumes. I need to follow this table and generate sequentially the indicated volumes. Let's say that entity is the same for a start (which is actually wrong and the next step will be selecting the entity simultaneously). Simulation should stop only after all the volumes have been generated. UPD: To make it even simpler. Can I just reset the FlowSource so that after it has generated everything is has (MaximumVolume), it resets the generated volume to zero and proceeds again with this amount?.. For, say, two or three times.

Hi, I like to count total number of entities types waiting in front of the servers.Say for example, i am having entity1,entity2,entity3.Each entity is produced from separate sources(source1,source2,source3 respectively) .I got 5 servers(S1,S2,S3,S4,S5). Entity 1 processed in S1-S3-S5 Entity 2 processed in S1-S2-S4 Entity 3 processed in S3-S4-S5 Each entity has different arrival rate. i like to create a expression to sum the total number of entity type 1 waiting in queue infront of the servers S1-S3-S5.if total number of entity type 1 waiting is greater than 100 numbers,the next coming entity type 1 from the source1 should leave the whole system( i mean sink without processing)similarly i like to count for entity2,entity3. Can anyone help me out? Thanks, R