Cumulative flow does not match stock
Posted: Tue Mar 26, 2024 12:56 pm
Dear,
I am modelling investments, but I encounter a problem.
The flow has the same value for every time step. However, the stock does not accumulate correctly... Only with timestep 1 does the stock have the same value as the cumulative flow. The stock does not accumulate correctly with smaller timesteps. It seems like some flow is fading away into mystery and not reaching the stock at all. Please see the attached screenshot of the behaviour in graphs of the stock and flow.
The equation for the stock (name stock: Cumulative investment primary) = incoming investment primary (flow). The initial value for the stock = incoming investment primary (flow).
The equation for the flow (name flow: incoming investment primary) = Investment primary aluminium (variable). This is a variable with some calculations.
How can I fix the model so that the stock has the same value as the cumulative flow with smaller timesteps (1/4 or 1/8)?
Looking forward to receiving the solution. If necessary, I can share some of the investment parts of the model.
Kind regards,
MKeeken
I am modelling investments, but I encounter a problem.
The flow has the same value for every time step. However, the stock does not accumulate correctly... Only with timestep 1 does the stock have the same value as the cumulative flow. The stock does not accumulate correctly with smaller timesteps. It seems like some flow is fading away into mystery and not reaching the stock at all. Please see the attached screenshot of the behaviour in graphs of the stock and flow.
The equation for the stock (name stock: Cumulative investment primary) = incoming investment primary (flow). The initial value for the stock = incoming investment primary (flow).
The equation for the flow (name flow: incoming investment primary) = Investment primary aluminium (variable). This is a variable with some calculations.
How can I fix the model so that the stock has the same value as the cumulative flow with smaller timesteps (1/4 or 1/8)?
Looking forward to receiving the solution. If necessary, I can share some of the investment parts of the model.
Kind regards,
MKeeken