Logistics and strategies evaluation of grain receiving operations using the system simulation approach.

摘要

This research investigated elevator configurations and management strategies to improve the unloading operation at a large inland terminal elevator vs. 12 different combinations of grain receiving patterns, including the segregation of non-GM soybeans. The study was done by using the system simulation approach. The average service time (defined as the average amount of time a truck spent at the elevator between arrival and departure) was chosen as the index to evaluate the performance of the unloading operation. Additionally, network modeling was implemented to tie together in one system model the elevator and the harvest-transportation supply chain to quantify performance as a function of delivery from farmers' fields (or on-farm handling facilities) and other elevators. The results showed that the performance of the unloading operation was heavily dependent on elevator configuration, management strategies and on incoming grain delivery patterns. The segregation of non-GM soybeans took less than 40 min.truck-1 during about 90% of the days in the harvest season. The facility could handle a non-GM soybeans flow of less than 2--3% of total soybeans deliveries without any significant disruption even on a busy day. Among the options tested, BATCH queue management (when trucks with the same grain type were served in batches rather than first-in, first-out [FIFO]) yielded time savings of about 27% when the unloading capacity used was above 72% of the theoretical one. For the enlargement of the pits, which allowed two hoppers of a semi truck trailer to be unloaded at the same time, the network model predicted up to a 17% increase in loads handled per day while reducing average service times by up to 34% compared to the actual elevator configuration. The traffic pattern change, which included the addition of an empty truck scale and the relocation of the probing station, yielded up to 23% in time savings versus the actual configuration. It was estimated that the traffic pattern change could be implemented for about one third of the costs of enlarging both existing receiving pits at this inland terminal elevator.