Ventana software support forum

Thanks Bob, I'll try that.

Gemma

Hi there, I think I'm asking a fairly simple thing here, but I can't think how to actually do it in Vensim. I would like to count the number of pulses that I have in a period, so say in 24 hours I may have had 5 pulses of 3 hours long. If I add this as a level, it gives me the wrong result - I need ...

Hi Bob, Thanks for your reply. Unfortunately, there is a bit more to each job than just starting and finishing. The model needs to send pulses down different routes to get to the finish point, some are redesignated, rejected etc. I need to show an accumulation of jobs after each process - the aim is...

Hi there, I've been pondering over a problem for ages now and can't seem to get round it. Hopefully someone will be able to help me? I have an input that is a set of pulses randomly distributed over one month. At this point I do not know the width ie time the pulse is to run for so I have set it to ...

Thanks again Bob.

However....................when I run the model I get an error as follows:

old target: simultaneous initial value equations involving: old target

Hello Bob - sorry I didn't make my problem clearer. I have a non linear cummulative graph. The time period is 0-100 hours. After 100 hours, the graph reaches 75 on the Y axis (number of widgets). Now, what I want to do is randomly sample that graph. So, say for instance the random generator gives me...

Hello. I was wondering if somebody could help me with a little problem. I have set up a variable number process (called 'variable 1'). I then have another process (called 'cummulative') which is the cummulative of a non-linear graph (therefore 'cumulative' is also non linear). What I want to do, is ...

Hi there, I'm wondering if anyone can help me with the following problem: My model contains a variable called "In On-Aircraft Maintenance" and this variable calculates the number of aircraft that are in maintenance bays. My model runs on time step 1 hour. I would like to get the results fr...

Thanks so much for your reply, it works just as I need!

Thanks for your reply, however I'm not sure it's what I'm looking for. To clarify, an aircraft comes in for a service (A Check) which takes 21 days. Directly following this, it will be tested which will take 5 days. At the moment, my model incorrectly shows that an aircraft is either in an A Check o...

Hi there, Further to my problem above, I think the main problem I am having is to do with the repeat time. It seems that at every time step while A or C Check are at 0, the pulse for testing is 1. I want testing to pulse for a value of 5 when the A or C Check first transitions from 1 to 0. Not for t...

Hi there, I'm trying to create a pulse of between 5-30 days to follow after an amalgamation of two previous pulses. The formula I'm using isn't working as I'd expected, perhaps someone has any ideas? I've basically got two pulses: A Check: PULSE TRAIN( 0, A Time+"Aircraft Wash Pre & Post&qu...

Thanks very much for your quick reply!

Hi there, I am trying to write a delay so the delay only takes place if there is something in the stock to delay. I have a pulse train sending the data into the model and these are delayed by a fixed time before they go into the "In Maintenance Post Spares" box. The delay statement that I'...