Cencic, O., & Frühwirth, R. (2025). On the advantage of assuming constant mass flow rates in discretized dynamic material flow models. Journal of Industrial Ecology, 29(6), 1977–1986. https://doi.org/10.1111/jiec.70102
When using discrete dynamic stock models in combination with lifetime distributions, the total amount of material transported in a period is implicitly assumed to be a spike at either the start or the end of the considered period. Depending on the choice, the residence time of materials in stock is either underestimated in the inflow-at-start approach or overestimated in the inflow-at-end approach. This paper proposes to solve this assignment problem by assuming the total mass flow to be evenly distributed over the period, using a continuous dynamic stock model, and discretizing the results afterward. It will be shown that this so-called uniform-inflow approach delivers more realistic results.
