Composting and Black Soldier Fly Integration Reduces Organic Waste Stock 39.64%

General Background: Increasing municipal refuse generation places substantial pressure on local processing facilities, particularly where biodegradable materials dominate incoming streams. Specific Background: The Tambakrejo Integrated Waste Processing Facility handles approximately 15,230 kg daily, exceeding its ideal processing capacity of 15,000 kg. Knowledge Gap: Existing local studies have primarily examined generation, composition, and facility planning, while comparative simulations of alternative biological treatment strategies remain limited. Aims: This study evaluates household organic waste management scenarios using system dynamics modeling. Causal loop diagrams, stock and flow diagrams, mathematical formulations, and simulation validation were developed using Vensim PLE for 2025–2030. Results: The model achieved a mean percentage error of 0.2041%. Without intervention, projected stock reached 3,564,670 kg in 2030. Both black soldier fly processing at 59.7% and combined composting at 24% with larval treatment at 35.7% produced 2,151,730 kg, representing a 39.64% reduction relative to baseline. The combined scenario was preferred because it generates different usable processing products. Novelty: The study compares biological processing alternatives using accumulated material as a dynamic simulation indicator at an operational facility serving multiple communities. Implications: The selected scenario provides a planning basis for phased implementation according to available processing capacity and operational conditions. Highlights: Simulation validation produced a mean percentage error of 0.2041%. Two alternative configurations achieved identical projected reductions of 39.64%. The combined scenario was preferred because it provides compost and larval biomass products.