Service Purchase Order
A service purchase order is an agreement to purchase the work that is identified in the service agreement. To complete the Line Items tab for a service order, you enter hours and rates, instead of quantities and amounts.
A service purchase order has a start date and an end date. These dates identify the time when services can be ordered.
A service purchase order also has "not to exceed" amounts. They set the maximum aggregate cost allowed for the services.
To change a service purchase order that was approved or final-printed, you must use a change order.