If you do not wish to use a customer schedule or schedule line, it can be cancelled. You can cancel a schedule as long as it has not been released.
If the schedule is changed to canceled, it is considered as invalid and a new schedule can be generated or created. If a schedule line is deleted, it will not be taken into account, when running the schedule further in the work flow.
Customer Schedule
Customer Schedules
Customer Schedule
Customer Schedules
Customer Schedule/Line
To cancel a schedule
To cancel a schedule line