A Schedule (the overall type of work) is further broken down into Service Categories. An Order is associated with a Service Category. When itemising the Order, only Items that have been associated with the selected Service Category are available to add to the Order.
For example, a General Electrical Schedule might be subdivided into several Service Categories: Cable Jointing, Cable Hauling, Pits & Vaults.
A Service Category can be linked to multiple Schedules but each association (Service Category to Schedule link) must be submitted as a separate new Service Category request. This creates a copy of the Service Category for each of the Schedules it is linked to.