- Greenhouse tomato growing processes are labor intensive, and the large numbers of workers involved in the various operations cause bottlenecks that affect costs and working efficiency. The main bottleneck points are in the trellising and harvesting stages, and in the transportation to the packinghouse. This study aimed to suggest improved working practices in tomato greenhouses by reducing manual labor. The study took place on a farm with 30 ha of tomato greenhouses located in southwest Israel. Work studies were conducted, and the working procedures were characterized. Two simulation models of the working procedures in tomato greenhouses were developed in ARENA and Microsoft Excel Visual Basic on the basis of statistical analysis of the work-study data. The Visual Basic simulation environment proved to be better suited to the agricultural environment. Several alternatives for the various work procedures were suggested and evaluated. The results indicate that fruit pickers should use a picking cart, progressing along the row in a batch advance method, and that longer rows are preferable and reduce working time. This could reduce manual labor by up to 32%. © 2007 American Society of Agricultural and Biological Engineers.