You reach the screen for creating a maintenance plan.
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You reach the initial screen for creating a single cycle plan.
If you specify a performance unit for the cycle, the system automatically selects the first counter suitable for the reference object as a default value.

You can only maintain the scheduling parameters for the maintenance plan if you have entered a unit in the section Interval for the cycle. From the unit, the system can recognize whether the single cycle plan is performance-based or time-based and provides the corresponding scheduling parameters.
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with quick info Create task list/general task list.
with quick info Create MaintItem.
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.See also
Profile for a General Maintenance Task List Defining a Default Value for a Maintenance Plan Category