For an introduction into Service with Advanced Execution, refer to this blog:
Introduction to Service with Advanced Execution
Execution Order Item
Items created in the Service with Advanced Execution process are called execution order items. The configuration or setup, the procedure to create and process such items in service transactions, the look and feel, and status lifecycle of execution order items is quite similar to that of other service items. However, the execution order item is modelled in S/4HANA Service with the new business object type BUS2000192 (Execution Order Item). Thus, an execution order item can be created using an item category which has the leading object type assigned as BUS2000192. Execution order items can be used in service order quotation or service order transactions. In general, an execution order item has a corresponding maintenance order, crucial for the strategic planning and seamless execution of the service. It is not possible to create service confirmations for an execution order item.

Execution Order Item
Some of the important fields available in the execution order item are
- Planning plant - plant where the maintenance tasks and corresponding materials required for the reference objects are planned and prepared.
- Work center - represent a person or department who is responsible for ensuring that the maintenance work is performed.
- Billing Relevance - specifies the type of billing to be performed for an item.
- DIP profile - it is a pre-requisite to use resource-related quotation process or resource-related billing.
- Execution status – reflects the current state of the maintenance order, ex. Execution Planning, In Execution, Execution Done, etc.
The planning plant and work center can be entered directly on the execution order item overview page. We can have different values for planning plant and work center in different execution order items of the same service transaction. Planning plant and work center can also be defaulted via the service organization unit and service employee group, respectively. Note that intercompany plants are not supported. This means planning plant must belong to the same company code as the sales organization of the service transaction.
The planning plant is editable until the creation of the corresponding billable maintenance order. On the other hand, the work center is editable until the execution status “Execution Done”.
The DIP profile and billing relevance can also be entered directly on the execution order item overview page and the values are entered per item. These are also enabled for defaulting via customizing of item category for the execution order item, under the assignment of Sales business transaction category. This can be done using the Customizing for Service under Transactions > Basic Settings > Define Item Category.
The execution status is not editable for the user and it can only be set by the system.
Billable maintenance order
A billable maintenance order is a pivotal component within the Service with Advanced Execution. Each billable maintenance order is connected to an execution order item. This enables the billing of costs linked to the maintenance tasks via execution order item.
Billable maintenance order can only be processed via SAP GUI transactions or via SAP GUI for HTML in the SAP Fiori Launchpad. These orders have a checkbox Billable in the header data of the maintenance order. This flag cannot be deselected retrospectively. It also has additional Sales-related (e.g.: Sales org., distribution channel, division) and Service-related fields (e.g.: Service product and quantity) on the header tab of the maintenance order. However, these fields are not editable on the maintenance order.

Sales and Service-related fields in Billable maintenance order
Since billable maintenance order is always connected to an execution order item, the service transaction ID and item number is displayed in the header tab of the maintenance order. System also persists the following information in the maintenance order: the service transaction ID, service item no. and service transaction type. See the fields SERVICE_DOC_TYPE, SERVICE_DOC_ID and SERVICE_DOC_ITEM_ID in the database table AFIH.