<b>Defintion.</b><br/>A combination of a category of worker <b>WorkerCategory</b> and a category of Equimpent  <b>EquipmentCategory</b> which can be combined and operate as an independently controllable unit to perform a certain <b>TaskCategory</b>. <br/><br/><b>Remark.</b><br/>Category is used to identify a particular category of equipment or workers, without identifying the individual worker or particular piece of equipment. A farm can have more workers or pieces of equipment of the same category.<br/>