US Patent 7310561 Identifying critical operations of a production process

Identifying an operation that is critical to meeting a due date of a production order includes identifying operations associated with the production order, obtaining schedules for the operations using infinite production planning, obtaining start intervals for the operations based on the schedules, selecting a target operation from the operations, and determining whether the target operation is critical to meeting the due date based on whether the target operation can be scheduled, using finite production planning, in a start interval obtained for the target operation.