Development of a transportation decision support system for rice seedling nurseries.

摘要

A decision-support system for transportation operations has been developed that should assist rice seedling nurseries with optimum planning. This was done using simulation software for five different types of transportation equipment, namely, a single-wheel cart, a dual-rail cart, a fork-lift with dual-rail carts, belt conveyors and a transport gantry Arena and the programming language Visual Basic were employed to develop a model that simulates the process of seedling input and output at a rice seedling nursery. Relevant data such as the size of hardening fields, the number of transporting equipment units and the number of available workers, etc., were inputed into the program in order to obtain the nursery throughput, the operational times and the utilization rate of workers under different conditions; the aim being to allow optimum decision making based on these various factors. An example based on a hardening field (90.4 m by 63.5 m) at 134 m from the sowing room was used to examine the system. The results showed that, for the seedling input operation, a transport gantry provided the best system throughput of 4,164 trays/h using eight workers. If the nursery used belt conveyors or a fork-lift with dual-rail carts, however, the throughputs were 2,549 and 1,725 trays/h, respectively. In output operations, if the number of workers was increased to 15, the transport gantry system throughput increased significantly to 5,885 trays/h. However, the belt conveyor only increased to 3,929 trays/h, which is still significantly lower.