[Using Time-Indexed Tables for row referencing]

Hello,

I'm using a time-indexed table in a model I'm working on, but it's not working as intended. I created a testing model to test the time-indexed referencing and it's not working either.

In the testing model, I have a simple SOURCE-SERVER-SINK model to test the Time-Indexed referencing. The way I was going to do that was by giving the capacity of the server values of 1 and 0 depending on the simulation time. This way I could see that every 1 minute periods, the server would allow passing (when capacity is 1) and disallow passing (when capacity is 0). Below, in Pic1 you can see 3 things: 1) property I created on the "Initial Capacity" cell of the server, 2) simulation time starting on 4/6/2015 at 12 am, and 3) status label "Table2.TimeIndexedRow" which should return the right row it's gonna be using depending on the simulation time.

 

 

Now, on Pic2, I attached a picture of my Table2, which is Time-Indexed. In this one, you can see two things: 1) Table set to time-indexed with a starting date of 4/6/2015 at 12 am (which matches the start of the simulation run) and an interval size of 1 minutes (which means that every 1 minute the table would look at the next row), and 2) Values for the property column "capacity", changing from 1 to 0 as explained before.

 

 

Now, when I run this model, if the model was working correctly, the server's capacity should be 1 from 12:00 to 12:01, and changed its capacity to 0 (disallowing passing) from 12:01 to 12:02 [and then continue doing so based on the values for the column "Capacity"]. However, what happens is that the capacity is just using the 1st row value (value of 1) and using it indefinitely - even though the status label I mentioned before for Table2.TimeIndexedRow is updating to 1,2,3,4... as intended.

I would really appreciate the help to solve this and answer any questions about the way I constructed this. Thanks!

[Processing time vs processing holding time]

Thank you very much for such a clear explanation. And that's good to know about the Capacity Utilization, because I'm using resources that have a capacity that varies over time.

[Processing time vs processing holding time]

Hello,

I have a quick question regarding the difference between the 2 metrics I highlighted in the attached picture. I'm done running the model and I'm not getting the results I expected, so I'm trying to go through everything and see where the problem is.

What I wanna know is, what's the average time that this server, DispoToLeave, spent processing (in a busy state) entities?

I really appreciate the help!

[Resource Capacity]

Hello,

I'm working on an emergency department (ED) model where I'm using both nurses and doctors as resources. At the ED, there is a 4:1 Patient to Nurse ratio, meaning that on average, a nurse takes care of 4 patients at the same time. When I was thinking about how to implement this logic on Simio, I looked at this option on the Seize step under Advanced options (you can see it on the picture I attached). I set the Units per Object to 0.25 - because I thought that every time a patient seizes a nurse, it will take out 0.25 out of 1 unit of capacity, instead of taking the whole 1, allowing for 3 other patients to seize her before she is completely busy.

However, this doesn't work, because I ran a model trace as I ran the model and the server is ignoring the seize because the "Units per object" is set to 0 (which is not, it's set to 0.25) - the exact model trace comment is:

"Ignoring resource release of type Specific 'Nurse'. The required capacity units per object '0' is not a positive quantity.".

Therefore, the model ignores the resource seize and processes the entity without the resource. Is this because this property field only works with integers? I thought of a work around by just multiplying my number of nurses by 4 to account for that, but that's not optimal. Would there be any other way of achieving this?

Thank you very much for the help!

[Using Rate Table Properties in Data Table]

OK, thank you for clearing that out for me

[Using Rate Table Properties in Data Table]

Hello,

I'm creating a model with different entities, and I want each entity to follow its own rate table. I created the Data Table (called "PatientData") that lists several properties such as mix, service times, priority, and Rate Table. I also created the 8 Rate tables (1 for each type of entity) and entered each one on the Data Table under the Rate Table column accordingly.

On my main source, I set the relevant properties as follows:

Entity Arrival Logic

Entity Type: PatientData.PatientType

Arrival Mode: Time Varying Arrival Rate

Rate Table: PatientData.RateTable

Rate Scale Factor: 1.0

Entities per arrival: 1

When I run the model, I get an Error at 0:00 with the following information:

Item: Source'MainEntr'

Item Property: Rate Table

A runtime error was detected at time 0.0 hours.

Error evaluating the value of property 'Rate Table'.

Invalid data table reference PatientData.

There might be a really easy fix, but I can't seem to find what I'm doing wrong. I was following the same way I'm used to calling columns from table. Thanks for the help!