What is the difference between Quantity Needed and Quantity Used on the Equipment/Part cross reference?

Quantity used is a historic count of the part issues. This field is automatically updated by SOMAX whenever that part is issued on a work order.

Quantity Needed is put in by you, manually, and usually remains the same while Quantity Used will go up over time.

The system will build the equipment/part cross reference over time as parts a issued to work orders but you can also add this cross reference manually.

When you are adding or editing the equipment on the Part Detail page, the "Quantity Needed" refers to how many of that part are on the machine.  

Example: A conveyor may need a total 4 bearings if you were going to replace all of that part at one time.