Search found 112 matches
- Tue Oct 22, 2019 1:18 pm
- Forum: Vensim
- Topic: Subscript Subrange
- Replies: 5
- Views: 3144
Re: Subscript Subrange
That's great, many thanks!
- Tue Oct 22, 2019 12:30 pm
- Forum: Vensim
- Topic: Subscript Subrange
- Replies: 5
- Views: 3144
Re: Subscript Subrange
Many thanks Tom. I've tried your suggestion, but I think I am doing something fundamentally wrong. I have created 4 subranges as follows: variant1 : (v1-v25) variant2 : (v26-v50) variant3 : (v51-v75) variant4: (v76-v100) Then: aircraft: (variant1, variant2, variant3, variant4) I have then created 4 ...
- Thu Oct 17, 2019 8:50 am
- Forum: Vensim
- Topic: Subscript Subrange
- Replies: 5
- Views: 3144
Subscript Subrange
Good morning/evening/afternoon. It has been a while since I last posted here. But myself (and the Company I work for) are slowly but surely getting back into the use of Vensim. I have a model that generates an aircraft flying programme. There are 100 aircraft (so I have a subscript called [aircraft]...
- Thu Jul 18, 2013 12:42 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
I've had a look at the model you attached Tom. The model I would want to use is the one with Poisson arrivals. However, "patients waiting 1" is behaving in a peculiar way (i.e. it never decreases). Do I need to change: QUEUE FIFO(admitting 0+arriving 0, admitting 0, flat, 0, 0 ) to QUEUE F...
- Fri Jul 12, 2013 9:42 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
Yes WITNESS is a discrete simulator developed by Lanner. It is getting a lot of traction within the Company for which I work largely because their salesman are very convincing and very persistent. That is something Ventana can't be accused of (rightly or wrongly). I suspect that, in general, I don't...
- Fri Jul 12, 2013 7:31 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
Just a reminder about the model modification, when you get a chance Tom.
I have spent the last four days on a WITNESS course and although it seems to me that WITNESS is more suited to the simulation of queues etc, I'm a little reluctant to use it because I much prefer the "feel" of Vensim.
I have spent the last four days on a WITNESS course and although it seems to me that WITNESS is more suited to the simulation of queues etc, I'm a little reluctant to use it because I much prefer the "feel" of Vensim.
- Tue Jul 09, 2013 5:47 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
Many thanks Tom.
- Mon Jul 08, 2013 8:49 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
Thanks Guido, Tom. My problem is this. You've already specified that max patients seen = 0.4 because the number of doctors is 4 and the length of an appointment 10 minutes. So what this implies to me is that, every time step (a maximum of ) 0.4 of "patients waiting" will be cleared, which ...
- Sat Jul 06, 2013 9:17 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
No, you'll find you're wrong.
Don't just look at the units, look at the outputs.
Don't just look at the units, look at the outputs.
- Sat Jul 06, 2013 9:06 am
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
Many thanks Tom.
Note that there is a slight error in your model.
patients seen = MIN(max patients seen,patients waiting)
and not
patients seen = MIN(max patients seen,patients waiting/average length of appointment)
Many thanks
Nik
Note that there is a slight error in your model.
patients seen = MIN(max patients seen,patients waiting)
and not
patients seen = MIN(max patients seen,patients waiting/average length of appointment)
Many thanks
Nik
- Mon Jul 01, 2013 2:52 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
I guess the easiest thing to do (and I know I'm talking to myself a bit here) is to set the number of doctors to: number of doctors / length of appointment = 0.4 This way only 0.4 of a patient can be seen in a minute. Not particularly elegant .......... and will it give a correct answer, particularl...
- Mon Jul 01, 2013 2:37 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Re: Waiting times in a doctor's surgery
The attached doesn't work because at the moment it does the following....... Once the average length of appointment is reached, patients are "seen" every minute depending on the number of doctors. i.e., in the attached, the number of doctors is 4. So, after the "average length of appo...
- Sun Jun 30, 2013 12:22 pm
- Forum: Vensim
- Topic: Waiting times in a doctor's surgery
- Replies: 21
- Views: 11373
Waiting times in a doctor's surgery
Good day everyone. I've built models in Vensim for a number of years now, but have never used Queues. The problem I have at the moment however, probably lends itself to Queues. I want to model the maximum waiting time for each patient who comes in and waits to be seen at a doctor's surgery. The pati...
- Thu Jan 27, 2011 1:01 pm
- Forum: Vensim
- Topic: Maximum of a variable
- Replies: 2
- Views: 2296
Re: Maximum of a variable
Perfect! Thanks very much.
Nik
Nik
- Wed Jan 26, 2011 4:15 pm
- Forum: Vensim
- Topic: Maximum of a variable
- Replies: 2
- Views: 2296
Maximum of a variable
Hello all. I realise that there is a GET DATA MAX that produces the maximum of a data range. However, I want to get a continuous account of the maximum of a variable. For instance, if a variable were to output the following sequence: 12,7,13,1,0,23,2,12,2,34 I would want another variable to give: 12...
- Mon Jan 24, 2011 2:54 pm
- Forum: Vensim
- Topic: Assigning data to subscript elements
- Replies: 14
- Views: 8442
Re: Assigning data to subscript elements
Thanks very much tom.
- Mon Jan 24, 2011 9:59 am
- Forum: Vensim
- Topic: Assigning data to subscript elements
- Replies: 14
- Views: 8442
Re: Assigning data to subscript elements
The allocation is done highest to lowest subscript. Is it possible to do it lowest to highest instead, so that subscript 1 gets allocated first as opposed to subscript 50 (assuming 50 subscripts)?
Thanks
Thanks
- Thu Jan 20, 2011 4:29 pm
- Forum: Vensim
- Topic: Assigning data to subscript elements
- Replies: 14
- Views: 8442
Re: Assigning data to subscript elements
Apologies Lee and Tom.
Yes - you're right............it does work
I made the mistake of looking at the graphs rather than looking at the tables.
Thanks again.
Nik
Yes - you're right............it does work
I made the mistake of looking at the graphs rather than looking at the tables.
Thanks again.
Nik
- Thu Jan 20, 2011 3:21 pm
- Forum: Vensim
- Topic: Assigning data to subscript elements
- Replies: 14
- Views: 8442
Re: Assigning data to subscript elements
Thanks Tom - unfortunately I need to track individual aircraft (and their progress through maintenance). Your model would be perfect - if I could get my version to work :? The Flying Programme does have pulses - but they are a long time in the future! For instance, there are pulses at 12381, 12386, ...
- Thu Jan 20, 2011 1:45 pm
- Forum: Vensim
- Topic: Assigning data to subscript elements
- Replies: 14
- Views: 8442
Re: Assigning data to subscript elements
No, still doesn't work for some reason. Irrespective of whether or not the dimensions are set (and I admit that they should be, but the model is by no means in its finished state yet), I don't understand why the "Mission Starts" function doesn't work. Any help more than gratefully recieved.
- Thu Jan 20, 2011 1:24 pm
- Forum: Vensim
- Topic: Assigning data to subscript elements
- Replies: 14
- Views: 8442
Re: Assigning data to subscript elements
The attached model is a part view of a much larger model. The p1 is a legacy subcript and I should have removed it. I'll remove and see if it clears the errors.
- Thu Jan 20, 2011 10:18 am
- Forum: Vensim
- Topic: Assigning data to subscript elements
- Replies: 14
- Views: 8442
Re: Assigning data to subscript elements
Thaks very much guys. Much appreciated. However - I'm obviously doing something silly, because my model doesn't run. You couldn't have a look could you please? "Mission Starts" is probably the culprit.
Nik
Nik
- Wed Jan 19, 2011 4:30 pm
- Forum: Vensim
- Topic: Assigning data to subscript elements
- Replies: 14
- Views: 8442
Assigning data to subscript elements
Hello all. I'm struggling to come up with a neat algorithm that does the following: I have a subscript with 20 elements (call them 20 planes). I have a flying programme made up of a series of pulses. The heights of the pulses are multiples of 1. 1 is the length of each flight, so if there is a pulse...
- Thu Dec 16, 2010 11:35 am
- Forum: Vensim
- Topic: Vensim versus Simul8
- Replies: 3
- Views: 4301
Re: Vensim versus Simul8
Thanks Lee - I was hoping you'd read my message, because you are well aware of the type of product/service I am talking about. I ended up going on a two day Simul8 course yesterday and Tuesday and I agree with everything you posted. Vensim is more suited to a higher level type of analysis when you a...
- Mon Dec 13, 2010 3:02 pm
- Forum: Vensim
- Topic: Vensim versus Simul8
- Replies: 3
- Views: 4301
Vensim versus Simul8
Hello all.
My company is currently in the process of deciding upon a standard through-life modelling tool.
The choice has basically boiled down to two. Vensim or Simul8.
Could the learned members please give an idea of what advantages/disadvantages Simul8 has over Vensim?
Thanks very much
Nik
My company is currently in the process of deciding upon a standard through-life modelling tool.
The choice has basically boiled down to two. Vensim or Simul8.
Could the learned members please give an idea of what advantages/disadvantages Simul8 has over Vensim?
Thanks very much
Nik