Use this window to define your own item types and connect them to a reference
item type. The reference item type determines how an item influences the work
scope and the cost build-up of the estimate. The purpose with customer
defined item types is that they provides the option to follow up costs on a
lower level than just the reference item type.
These are the reference item
types;
It is also possible to connect an estimate type to a user defined item type. Such connection has an impact on the selection of item types when creating a new item header. An item type with an estimate type connected appears only in the list of value if the estimate type is defined in the estimate header.
If no estimate type is connected to a user defined item type then it is always included in the selection of possible item types when creating a new item header, this independent of if the estimate header is connected to an estimate type or not.