what's happening is a strange thing. If I set a infinite capacity on the buffers the MUs block on the first two buffers, and only after they are filled the MUs goes to the machines and the simulation procede.
but if I set a finite capacity it doesn't happen, and MUs goes normally in the simulation.
WHY?? (look at the attachment)
I think it happens because the Source produces parts with the setting 'Number Adjustable' and the distribution represents a range in time instead of an interval.
Thus, the creation of all parts is scheduled before any other event. And an infinite buffer right next to the source allows it to do that.
If you have a finite buffer, the source is blocked and cannot produce any more parts.
See help topic on 'Number Adjustable'.. That might be the reason for this behaviour.
That depends on how you want to use the Poisson's distribution for creating the MUs.
If your intent was to have the Interval between generation of MUs to be based on the distribution, you should change the Time of Creation in the Source object to 'Interval Adjustable' in place of the 'Number adjustable'..
From what I understand now, is that the problem is that the rate of creating the parts is very high compared to the processing time? Please correct me if I have a wrong understanding..
The lambda parameter is set to a very low value here.
The lambda value does not represent the number of occurences per second.
It represents the time interval between occurences in seconds.
I had a look at both of your posted models.
You are creating 4 different parts ( A,B,C,D)
with a randomly set frequency.
Ready to leave the source, each part is directed
through the flow control ( FCSource)
either to Buffer1 or Buffer2 .
With infinite buffer capacities there is always enough buffer capacity to
receive the directed MUs.
With finite ( in this case 2X8 ) buffer capacities the source will block
as soon as one buffer is filled with 8 parts and the last part to leave
is directed to the full buffer.
The source will produce the next part as soon as the filled buffer releases on part
This is according to the set tablefiles between 20 and 36 min.
With infinite capacities it will go on (endlessly) producing parts.
I have checked for 1 min simulation time
the source produces:
16 parts ( 2 x 8 places)
1334 parts (infinite)
What you are seeing in the infinite version is just the
continuous production of (thousands of) MUs whilst of the stations are finishing
there cycle ( after 20min -36.0min) .Nothing else !
Creating these amounts of MUs takes (real) time for the system but has no effect
on the simulated data !
Therefore the suggestion I can give in this case is not to use infinite buffers
in connection with Sources with a very low cycle time as this constellation is just consuming
computer resources for not required MUs in the infinite Buffers.
Set the buffer capacity to aligned size which does not affect your Simulation.
ok. Now I've understood.
last questions I want to ask you is:
1) If i want the average processing time, have I to look in the statistic report-->working time--->mean value? Or is there an other way?
2) for the average time between two arrival, have I to llok in the statistic report og the resource---> waiting time---> mean value?