1. SAP Help Portal - Maintenance Plan Category: "In Customizing for Plant Maintenance and Customer Service
you can define the maintenance plan categories you require... For each maintenance plan category
you must specify which call object the system should generate for a maintenance call." This confirms the Call object parameter.
Source: SAP S/4HANA Documentation
"Maintenance Plan Category".
2. SAP Help Portal - Configure Maintenance Plan Categories: The configuration settings for a maintenance plan category explicitly require an Order type if the call object is a maintenance order.
Source: SAP S/4HANA Implementation Guide (IMG)
Path: Plant Maintenance and Customer Service -> Maintenance Plans
Work Centers
Task Lists and PRTs -> Maintenance Plans -> Configure Maintenance Plan Categories.
3. SAP Help Portal - Scheduling Parameters for a Maintenance Plan: "Completion requirement: If you set this indicator
the preceding maintenance call object (for example
maintenance order) must be completed before the system can generate the next maintenance call object." This setting
available in the plan and often defaulted from the category
makes the Completion date a key controlling parameter.
Source: SAP S/4HANA Documentation
"Scheduling Parameters for a Maintenance Plan".