Net Stock equal to zero

[tljenkin]

I am teaching a course in service systems and using Vensim to model some system processes.

We have played a board "game" and are now working on simulating the game play in Vensim.

The way the game is played, the net WIP should always be zero at the end of each time period. Thus at each time step or iteration a certain amount of work, x, enters the stock (WIP) and is processed in that time period by available workers, y and leaves giving a net stock of zero.

I understand this may be bad system dynamics, but the rule is there is no accumuation of WIP unless there are not enough workers. Thus if I have enough workers in any period to process all incoming WIP the net stock level shuold be zero.

At best I get a net accumulation in WIP equal to the amount of incoming work (initial WIP value is zero) and it stays that way through the end to the time runs of 50 iterations. Both incoming rate and outgoing rate are constant and equal.

Thanks for any help that is offered.

[Administrator]

Can you upload the model you are using?

Tony.