Lecture 21 Principles of Grain Handling Systems

1. There will always be a bottleneck in any materials handling system. 2. If design capacity is not being obtained, always increase resource expenditures for increasing capacity of the bottleneck until the cost of adding one additional unit of capacity exceeds the benefits. generally some other component becomes the bottleneck... or... the design capacity is obtained. generally some other component becomes the bottleneck... or... the design capacity is obtained. 3. If intelligent decisions are to be made concerning the performance of a materials handling system, the decision maker must be aware of what is happening and its associated time of occurrence withing the system. Procedures used to determine where the bottleneck occurs... Stopwatch Calculator Computer simulation Computer simulation

Event Method of Determining Performance Efficiency 1. ID activities that have a definite start and stop time 2. Determine the start and stop times 3. Calculate the theoretical time needed for one complete operation 4. Observe the actual system and determine actual time needed for the operation 5. Efficiency formula: % efficiency = Theoretical time * 100 Actual time

Example - Combine 1. Combine starts harvesting 2. Combine stops harvesting when tank is full 3. Truck moves into place 4. Combine unloads grain 5. Combine completes unloading cycle % efficiency = 30 min * 100 = 66.7% 45 min or Theoretical capacity of combine vs bushels harvested.... % efficiency = 1,200 bu * 100 = 66.7% 1,800 bu