Dynamics System Modeling for Rice Stock

Abstract

Rice production in Indonesia is characterized by large number of people and institutions involved in the business and wide spread of distribution area. There are two kinds of rice sources namely in country farmers production and the imported one. From these two sources rice is distributed throughout the country through many channels of marketing and distribution. The dynamics of rice supply and its distribution is mainly affected by factors of season, harvest field availability and its productivity, rate of harvesting failure, in country prices, import barrier, government involvement, and quality of infrastructure. A system dynamics model of rice stock was constructed using ithinkTM software. The model attempts to figure out the behaviour of rice stock system by simulation technique. The system was represented by ten subsystems which are interacting one to another. These ten subsystems were farmers, rice millings, KUD, collector traders, Bulog, grociers, importers, national stock. The interaction between each subsystem is depicted by a causal diagram, following the systems dynamics approach. The sensitivity of the model can be tested by running the model under certain set of values of key parameters and variables. The simulation resulted in two important findings. First, the model was able to picture the dynamics of rice distribution among ten subsystems assigned. Second, the value of stocks at each subsystem were considerably resembling the actual stocks at each subsystem. These results enabled the model to be used as a predicting tool or simulation tool for rice stock distribution.