Simulation model for the sequential in-field machinery operations in a potato production system

A simulation model for the sequential potato operations was developed and validated.The model can be implemented as an operation management tool for potato production.Errors in prediction of field efficiency and capacity were less than 4.8%, 6.1%, respectively. In potato production multiple sequential operations have to be carried out during the yearly production, and each operation may have its own set of operational features, given by the used machinery. An optimal planning for one operation may lead to restrictions and reduced efficiency to later operations. Therefore, there is a need to develop an approach for predicting and optimizing the overall performance of all operations, given a selected field and the required machines. The work processes with corresponding sequential decisions of each operation involved in the potato production were described by using IDEF modelling approach and implemented using the MATLAB? programming software. Experiments for all the relevant operations in potato farming (bed forming, stone separation, planting, spraying and harvesting) were carried out and monitored in four experimental fields to quantify the set of input parameters and to validate the simulation model. The simulation model predicted the field efficiency (the ratio of the time a machine is effectively working to the total time committed to the whole operation) and the field capacity (the area processed per unit of time) with satisfactory precision for all operations in all fields. The errors in prediction of the field efficiency and the field capacity ranged from 0.46% to 4.84% and from 0.72% to 6.06%, respectively. In addition, the capability of using the developed model as a management-planning tool for decision support on operational decisions (e.g. driving direction, reloading position) and machinery dimensioning (e.g. tank/hopper size) was demonstrated.