COMBINING PULSE AND DELAY

[irene]

hi,
I am new here and i have this problem. I have an inflow (order rate) to a level that is a pulse train (order rate = PULSE TRAIN( {1} , {1} , {7} , {100} ) but the outflow (order arrival rate) is a delay (outflow= DELAY FIXED( {order rate} , {20} , {0} ). I want to bring the model to equilibrium state (inflow=outflow) but i cannot because i have to tell the model that {init} (0 in the DELAY FIXED function) follows the PULSE TRAIN pattern (the order arrives every 7 days) . How can i do that? is there a way because no matter what i do it brings back the order rate (i.e 200) for every time step and i want this number to appear only on specific times (every 7 days). By the way I use VENSIM.
Looking forward for some help.
Irene

[Administrator]

Can you post the model so we can take a look to get a better understanding?

[irene]

I have it posted. All i want is to bring it to equilibrium.
Thank you for your help.
Irene

[Administrator]

You will have to do something like I've done in the attached model (deal with the orders during the initial period).

[irene]

thank you very much.
i have two questions.
1. do you think it is better to use "Time >=INITIAL TIME" in the "if then else" formula in order to include time = 1?
2. in the order receipt rate i have a value at time 21 and not 22 as i should and therefore the 7 days interval changes and supply line becomes negative at time 22 (it is because of the Time < Input Replenishment Time in the "if then else" formula) . I want my level to be 0 at all times to have equilibrium. What should i do? (i have included the model with the alteration).
thanks again,
PS: please bear in mind that i am self-tough and my background is poor, so if you find the above naive , feel free to tell me !!!

[irene]

i found it...
thanks for your help.
irene